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1
The Prisoner’s Dilemma: An (Un)Natural Experiment
from Nazi Germany
Wayne Geerling (Pennsylvania State University) *
Gary Magee (Monash University) +
Robert Brooks (Monash University) #
Abstract
This study examines a real-world, one-shot, high-stakes
prisoner’s dilemma, very similar to the story often related in
textbooks. The ‘prisoners’ were individuals, aged between 15
and 62, charged with high treason in Nazi Germany between
1933 and 1945. They faced a choice between cooperation and
defection. We find that even in such extreme settings
significant cooperation rates remain, though at rates lower
than in games undertaken in controlled circumstances or on
game shows, suggesting that the size of the stake does
influence social preferences. We also find evidence that age,
education, affiliations and a sense of community also play
roles.
DRAFT: NOT to be quoted from or cited without authors’ permission
* Department of Economics, Pennsylvania State University, 306 Kern Building, University Park,
PA 16802, UNITED STATES OF AMERICA. Tel: +1 8148673300. Email: [email protected] + Department of Economics, Monash University and Department of Economics and
Econometrics, University of Johannesburg. Faculty of Business and Economics, Building S, Level 9, Monash University, PO Box 197, Caulfield East, Vic 3145, AUSTRALIA. Tel: +61 399031307. Email: [email protected] # Department of Econometrics and Business Statistics, Building S, Level 9, Monash University,
PO Box 197, Caulfield East, Vic 3145, AUSTRALIA. Tel: +61 399031423. Email: [email protected]
2
I
For many, if indeed not most, the study of game theory begins with the
prisoner’s dilemma. Its story and lessons are familiar to all who have taken at
least some undergraduate economics. The game’s influence, however, extends
far beyond that. Its insights are widely drawn upon by researchers not only in
economics, but in mathematics, decision theory, philosophy and right across
the social, behavioral and biological sciences (Dixit & Nalebuff 2008; Kuhn,
2009; Sally, 1995).
The striking prediction of the one-shot prisoner’s dilemma – that defection is
the dominant strategy – follows logically from the assumptions of the game.
But what evidence is there in the real world for the predictions of the
prisoner’s dilemma? Most commonly, proof of its validity is found in the fact
that certain events appear to parallel the conditions of the prisoner’s dilemma.
Whether it be the rivalry of the superpowers, the difficulty of obtaining
international agreements on greenhouse gases, drug taking in elite sports, or
even the actions of the fictional characters in Jane Austen novels, the agents in
each of these scenarios appear to conform with the expectations of the
dilemma (Dixit et al., 2009; Dixit & Nalebuff 2008; Chwe 2013). These
exercises demonstrate that the outcomes of the dilemma can be mapped onto a
number of situations, many of which are themselves purely hypothetical.
These are arguments by analogy, not explicit tests of the dilemma’s empirical
reality.
Aspects of that reality, however, have been captured in other ways. Controlled
experiments conducted within the laboratory or in the field and analysis of the
outcomes of game shows, whose rules incorporate the prisoner’s dilemma,
have provided rich and valuable sources of data and insight. Among other
things, they show that, contrary to expectation, between 30 to 50 per cent of
participants from all backgrounds opt to cooperate; that women and people
over 40 are more inclined to be cooperative than males or young people; and
3
that the magnitude of the stake does not appear to have much bearing on the
degree of cooperation (van den Assem et al., 2012; Dixit & Nalebuff 2008;
List, 2004, 2006; Sally, 1995; Roth, 1995; Khadjavi & Lange, 2013).
Yet how translatable are such findings to the world beyond the laboratory and
game show? It is not unfair to say that laboratory experiments and game
shows hardly take place in typical or naturally occurring contexts. In their own
way, each is somewhat contrived; one for reasons of scientific control, the
other for the sake of entertainment. And participants entering either setting are
fully aware of their fabricated natures. They know they are being observed and
recorded and may alter their behavior accordingly. They know this is a game
that they can ‘play to win’ because the consequences of loss are not real (List,
2006). For the most part, any loss incurred has no bearing on life outside the
studio or the laboratory. Expressed differently, the stakes involved are
inevitably low. In experiments, they may be as small as a handful of dollars,
either paid in cash or in kind (Carpenter et al., 2005). Khadjavi and Lange’s
(2013) recent simultaneous prisoner’s dilemma game with female inmates
from a penitentiary in Lower Saxony, for example, expressed its stakes, for
reasons of prison rules, in terms of small quantities of instant coffee, tobacco
and phone credit. Still, the monetary value of the maximum amount winnable
in the actual game, in whichever form it was taken, was just under €2.
In game shows there is, to be sure, the potential of more significant gains. In
one show, Friends and Foe, the stake went as high as $22,000, though the
mean stake was around $3,500 (List, 2004, 2006; Oberholzer-Gee et al., 2003,
2010). In another, the UK program, Golden Balls, players competed for
jackpots with a mean value of £13,416 and median of £4,300, whereas in the
Dutch TV game show Will (s)he share or not?, the median stake was €1,683
(van der Assem et al., 2012; Belot et al., 2010). No doubt, these prizes
represent notable increases on the gains on offer in the experimental
laboratory, including those in low-income countries (Slonim & Roth, 1998;
4
Cameron, 1999; Kocher et al., 2008), yet in terms of real-world dilemmas,
even these higher game show stakes must be considered relatively low. After
all, lives are not hanging in the balance; futures and fates are not being
determined by a single decision. Moreover, in both the laboratory and game
show, stakes are invariably expressed in terms of what can be won: the money
you did not have before, but which you can take home with you. There is no
loss to the participant other than the opportunity cost of making the wrong
choice. Given the widespread prevalence of loss aversion (Kahneman &
Tversky, 1979), such stakes couched purely in pecuniary gains are unlikely to
elicit as much concern as those that involve the participant potentially giving
up something they already have.
Therefore, the findings of neither the laboratory nor game show lend
themselves easily to generalization (Levitt & List, 2008). The problem is that
there are few alternatives to which researchers can turn. As List (2006, p. 470)
has noted, to the best of his knowledge, ‘there does not exist an empirical
examination of behavior in a high-stakes game that mirrors the classic
prisoner’s dilemma tale’.
This paper fills that gap. It offers a rare, real-world natural experiment of a
high-stakes, one-shot, classic prisoner’s dilemma game. The experiment,
which took place in Nazi Germany between 1933 and 1945, was ‘real’ in three
respects. First, it arose out of a context that, while perverse, inhumane and
thoroughly repellent, was not in any way contrived or perceived as artificial to
those involved. Indeed, unlike previous studies which have used prisoners as
their subjects (Khadjavi & Lange, 2013; Churma et al., 2010; Birkeland et al.,
2011), the prisoners in this natural experiment were not – and knew they were
not – simply playing a game concocted by a researcher. Second, it was real
because it was a true prisoner’s dilemma, that is, the ‘game’ that was played
out occurred in precisely the same setting as that which has given the dilemma
its name. Thus, the natural experiment uniquely allows us to observe how
5
actual prisoners placed in the classic prisoner’s dilemma setting actually
behaved. Finally, the reality of the experiment is underscored by the truly high
stakes the prisoners were playing for: nothing less than their lives and liberty.
Several interesting findings emerge from studying this natural experiment. As
in previous literature, we find that even in such extreme settings significant
cooperation rates remain. The lower rate of cooperation vis-à-vis games
undertaken in the laboratory or on game shows, however, suggests that the
size of the stake does influence the rate of cooperation. We also find evidence
that age, education, beliefs, political and social affiliations, sense of
community and identity also play roles.
The remainder of this study proceeds as follows. Section 2 discusses the
background and setting of the natural experiment. Section 3 describes the data
used in the paper and how it was collected. Section 4 discusses factors that in
theory encourage cooperation within a prisoner’s dilemma and assesses their
relevance to this context. Section 5 summarizes the results of our estimations
of the prisoner’s choice to defect or cooperate. Section 6 concludes.
II. The Natural Experiment
The natural experiment that this paper examines was discovered by the authors
while undertaking research on juvenile resistance to the Nazi regime between
1933 and 1945. This project studied juveniles and the adults with whom they
collaborated, whose resistance was considered serious enough by the Nazi
authorities for them to be indicted and tried for high treason, an offense, which
on conviction, typically resulted in execution or lengthy spells of
imprisonment (Geerling et al., 2013).
6
All individuals in our sample were thus charged with the same, serious offense:
high treason. Prior to their appearance before the People’s Court
(Volksgerichtshof), each resister was investigated, arrested and interrogated.
During interrogation, resisters were separated from their collaborators and
encouraged to confess and assist the authorities in their investigations.
Information obtained through these interrogations benefited the defendants
who provided it and was also used by the authorities against their co-
defendants. Take, for instance, the typical case of two resisters from Hamburg,
who after spending fourteen months in custody, were both convicted in
October 1938 of the high treasonous offences of belonging to a banned
organization and distributing illegal writings. Of these two resisters, one
defected and provided information to the authorities; the other did not. In
sentencing, the defector received a 5 year penitentiary term with all 14 months
of his time in custody deducted because, as the judge explained in summing up,
he had ‘confessed and helped clear up all the facts of the case’. By contrast,
his co-defendant, who had chosen not to defect, was given an 8 year
penitentiary term with only 6 of the 14 months spent in custody being counted
against it. His harsher sentence was attributed by the judge to the fact that he
had, despite ‘the mountain of evidence, foolishly denied every activity’,
behavior which only served ‘to undermine his credibility’. The testimony of
his co-accused, who had defected, however, was accepted by the Court, ‘as
corresponding to the truth’.1
The temptation for resisters to defect was thus strong. By doing so, one could
potentially save one’s life, reduce one’s sentence, or enable oneself to avoid
torture and hard labor. It was realistic for those detained to believe that such
payoffs existed because Nazi sentencing did both exhibit discretion and
reward defection. Tables 1 and 2 show those payoffs in terms of both the
1 Bundesarchiv, Case Files of the Volksgerichtshof, Case Number 1H 26/38,
14 October 1938, Verdict, pp. 9 and 15.
7
likelihood of receiving the death penalty and average standardized months in
prison.
Table 1. Payoffs in terms of probability of being executed
Defendant
Defected Cooperated
Co-defendant Defected 0.44; 0.44 0.10; 0.50
Cooperated 0.52; 0.10 0.17; 0.17
Table 2. Payoffs in terms of standardized months in prison
Defendant
Defected Cooperated
Co-defendant Defected 197; 197 98; 229
Cooperated 229; 98 118; 118 Note: Standardized months were calculated in the following way.
1 month in prison = 1 month in prison
1 month in penitentiary = 1.5 months in prison
Execution = 30 years in prison = 360 months in prison
Except when everyone defected, these tables show that those who chose to
defect tended to receive either less harsh forms of punishment (prison rather
than execution, for example), shorter terms in prison or both. The lightest
collective penalty overall, however, occurred when no-one defected. Yet, as
with the classic prisoner’s dilemma, defection was the dominant strategy for
resisters in this situation. They faced no external consequences for pursuing
such a strategy either. Any fear defectors might have felt of punishment by
other opponents of the regime was greatly minimized by the fact that because
of the secrecy involved, not to mention the disinformation publicly spread by
the authorities, no one could know for certain who had defected and who had
not.2 Indeed, we ourselves have only been able to determine whether defection
2 Hearings of the People’s Court were not open to the public. Access was
restricted to carefully picked civil servants, military officers and party officials.
Nor were documents, testimonies, or judges’ summaries publicly available.
8
occurred by reviewing internal court documents not publically available at the
time. The probability of external retaliation for defection was thus extremely
low. Nor was there a long-term to think of. Their actions had no implications
for future cases. No resister reappeared before any Nazi court.
The resisters thus found themselves in a genuine one-shot, high-stakes, multi-
player prisoner’s dilemma. It was a game where it was reasonable for each
resister to believe that one would always get a benefit from defection
irrespective of what others did, but that the benefits would be greatest when
no-one else in the case defected. Conversely, cooperation brought no benefits
unless everyone else in the case cooperated. A single defection completely
undermined cooperation: there was no positive externality from cooperation
unless everyone cooperated.3 In such a scenario, defection was the dominant
Indeed, the cases themselves were not reported in the media, except on rare
occasions when the government saw propaganda value in reporting a verdict.
Even in these instances, no details of the reasoning underpinning the verdict
were provided. Moreover, from the time of arrest and after sentencing, the
ability of political prisoners to communicate with each other and with the
outside world was severally and consciously constrained by the authorities. If
allowed contact at all, their letters were heavily censored and visits from
family members very closely monitored and controlled for content. Beyond
expressing remorse for their actions, prisoners were forbidden to talk about
their case or politics. 3 Even then, there were limits to the benefits. As Tables 1 and 2 show, while a
cooperative equilibrium led to lighter sentencing for all, it did not mean
release. It is important to remember that all defendants had been accused of
attempting to oppose and overthrow the Nazi regime. Indeed, most had been
monitored by the Gestapo for months before arrest and all did have at least
some sort of affiliation or connection with resistance activities. These
circumstances have two implications for how we analyze the situation. First,
they mean we can be confident that no defendants in this natural experiment
chose to cooperate simply because they were ‘innocent’ and thus had nothing
to confess. Second, mutual cooperation between co-defendants, when it
occurred, typically lessened the information at the Nazi’s disposal, rather than
completely deprived them of it. This meant that mutual cooperation tended to
result in a reduction in the harshness of sentences handed down rather than
outright acquittal or the dropping of charges.
9
strategy. Any duress experienced by resisters in reaching their decisions
merely amplified an already strong rationale for defection.4
III. Data
This paper examines the choice to defect or not of a sample of resisters
charged with high treason in Nazi Germany between 1933 and 1945. All 29
cases from this era involving juvenile resistance, and for which there were
multiple resisters, are included. A juvenile is defined here, as it had been in
German law since the Weimar Republic, as someone who was under 18 years
of age at the time of the alleged ‘crime’ (Geerling et al., 2013). In total, there
are 181 resisters in the database, of which 131 were males and 50 females. Of
the males, 45 were juveniles. Ten of the 50 female resisters were juveniles.
30.4 per cent (55 people) of the resisters were juveniles and 69.6 per cent
adults (126 people).
The database contains a wide variety of case sizes and resisters. There are
cases with as few as two defendants and some with as many as 13. The
majority of cases, though, had five or fewer defendants (median = 5). The ages
of resisters at the time of indictment ranged from as young as fifteen right up
to sixty-two, with a median age of twenty-five.
4 We do not subscribe to the view that torture is an external force which
induces irrationality and, hence, distorts the ‘game’s’ outcome. Rather, we see
torture and duress as natural parts of the process of interrogation, in which the
prisoners found themselves. When taken into custody, prisoners expected
physical and psychological duress to be used. As such, enduring or limiting
the extent of torture represented parts of the implicit payoffs faced by
prisoners in this real-world dilemma. The economic role of torture was thus to
shift payoffs – or, in other words, the stakes involved – to a position that made
defection even more strongly the dominant strategy. We do not believe that
individuals cease to be rational when duress is introduced.
10
Table 3: Number of defendants per case and age at indictment of resisters
Cases with: Number
of cases
Age at
Indictment
Number of
defendants
Age at
Indictment
Number of
defendants
2 defendants 2 15 1 39 2
3 defendants 5 16 7 40 5
4 defendants 7 17 13 41 2
5 defendants 3 18 23 42 3
6 defendants 1 19 8 43 2
7 defendants 2 20 13 44 1
8 defendants 1 21 7 45 2
9 defendants 1 22 4 46 6
10 defendants 2 23 8 47 3
11 defendants 0 24 6 48 1
12 defendants 3 25 8 49 4
13 defendants 2 26 1 50 3
27 3 51 1
28 2 52 1
29 2 53 2
30 0 54 1
31 2 55 2
32 4 56 2
33 5 57 1
34 4 58 2
35 2 59 0
36 4 60 3
37 3 61 0
38 1 62 1
The data used in this paper were extracted from the official state records of
juvenile cases tried before the People’s Court collated by the Resistance as
High Treason (Widerstand als Hochverrat) project, which combined material
on resistance groups stored in the archives of the Federal Republic of
Germany and Austria with previously inaccessible files from the former
German Democratic Republic, Prague and Moscow (Zarusky & Mehringer,
1998). The microfiche series it generated contains among other things the
court files that document the judicial prosecution of juveniles (and those who
11
abetted them) charged with high treason. These files include a wealth of
information on the indictment, investigation and trial of each defendant.
Through searching these records, we have been able to reconstruct the profiles,
family backgrounds, and influences of all resisters who were juveniles, or
collaborated with juvenile resisters, charged with high treason between 1933
and 1945. Wherever possible, we have crosschecked and supplemented our
information with the entries for individual resisters found in the leading
encyclopedias of German resistance (Steinbach & Tuchel, 1998, 2000). This
database not only affords a new perspective on those German and Austrian
youths who resisted the Nazi state, but, with careful reading of each individual
case file, also enables us to determine which resister had defected during
interrogation.
This was possible because Gestapo internal reports (i.e. they were not intended
for public disclosure) of investigations, retained in the unpublished case files,
indictments and verdicts of the People’s Court, would freely refer to a
resister’s ‘full and frank’ confession or how the evidence provided by them
was used to convict other resisters.5 For example, according to one such report,
it was noted that during his interrogation, one 18-year old juvenile from
Vienna charged with writing anti-Nazi pamphlets had made a full confession.
He had also admitted to ripping to pieces an oil painting of Hitler, though now:
‘he feels shame for his actions and recognizes his error.’ Furthermore, he
wished to atone by writing a new work ‘in which he will show his change of
heart toward National Socialism’.6 Similarly, in another report about the
interrogation of a resister from Leipzig, it was stated that the prisoner after
5 We have read hundreds of internal documents and found no evidence of
interrogators fabricating reports or confessions. Indeed, whenever a prisoner
subsequently denied or retracted elements of an earlier statement, this was
clearly recorded in later reports. Such a practice suggests that fabrication, if it
occurred at all, was not common. 6 Zarusky & Mehringer (1998), Microfiche 0428, Case Number 7J 104/44,
Indictment p. 3, Verdict p. 4.
12
much resistance only ‘brought himself to a confession after being told that
everyone had already spoken’.7 Failures to defect were also recorded by
Gestapo interrogators and were typically attributed to the resisters’ alleged
obstinacy, remorselessness, immorality or just complete lack of honor. Thus,
in the Gestapo files of one Austrian woman, it was reported that despite
‘persistent reminders to be honest’ stretching over four months, she refused to
cooperate with investigators. She was, nevertheless, convicted of high treason
and sentenced to five years in prison.8
This Austrian resister was far from unique in not defecting. In 41.4 per cent of
the cases at least one defendant did not defect. In two cases (6.9 per cent) all
of the defendants opted to cooperate. The majority of cases (58.6 per cent)
resulted in the expected non-cooperative equilibrium. As for individuals, 31,
or 17.1 per cent, chose cooperation. Of those 31 resisters who cooperated, 80.6
per cent had at least one co-defendants defect on them. Only 6 resisters had all
of their co-defendants cooperate as well. By contrast, 55.2 per cent of resisters
were involved in cases where all defendants defected.
The motivations to defect were strong, but not always overwhelming. With
stakes that were life-threatening, overall rates of cooperation fell markedly
from the 30 to 50 per cent typically exhibited in experimental or game show
conditions, including those conducted on prisoners (Khadjavi & Lange, 2013;
Churma et al., 2010; Birkeland, 2011), to 17.1 per cent. Thus, stakes do seem
to matter. Interestingly, though, they are not all that matter. Even the threat of
torture and execution does not appear to have been able to snub out all desire
to cooperate.
7 Bundesarchiv, Case Files of the Volksgerichtshof, VGH/Z H 286, Leipzig
Gestapo Report, 12 July 1938, Sonderband Lippert, p. 16. 8 Bundesarchiv, Case Files of the Volksgerichtshof, VGH/Z K, Gestapo Report,
14 July 1942, p. 34. Dokumentation Österreichischen Widerstandes, Case Files
of the Volksgerichtshof, DÖW 20000/K653.
13
Table 4. Cooperation rates by cases
Cases where: Number (percentage) of cases
All defendants cooperated 2 (6.9)
Some but not all defendants
cooperated
10 (34.5)
No defendants cooperated 17 (58.6)
Table 5. Cooperation and defection rates by defendants and co-
defendants actions, numbers and percentages (in brackets).
Defendant
Defected Cooperated Total
Co-defendants Defected 100 (55.2) 25 (13.8) 125
Cooperated 50 (27.7) 6 (3.3) 56
Total 150 (82.9) 31 (17.1) 181
Decomposing cooperation further reveals striking differences between genders
and age groups. Table 6 divides all resisters into four distinct age groups:
juveniles (15 to 17 year olds), young adults (18 to 27 year olds), mature adults
(28 to 40 year olds), and older adults (more than 40 years old). Each age group
is further divided by gender.
Table 6 shows that female resisters were noticeably more likely to defect than
their male counterparts (92 per cent compared to 79.4 per cent). This disparity
between the genders appears to hold across all ages groups, except for mature
adults where the number of female resisters are probably too small to draw
strong conclusions. This finding, discussed in Sections 5 and 6, stands in stark
contrast to the existing literature which often observes the reverse (Oberholzer
et al., 2003; List, 2006).
14
Table 6. Cooperation and defection rates by age and gender
All Ages
Combined
Gender Number
(percentage) who
defected
Number
(percentage) who
cooperated
Total
Male 104 (79.4) 27 (20.6) 131
Female 46 (92.0) 4 (8.0) 50
Total 150 (82.9) 31 (17.1) 181
Juveniles
(up to 18
years)
Number
(percentage) who
defected
Number
(percentage) who
cooperated
Total
Male 34 (75.6) 11 (24.4) 45
Female 9 (90.0) 1 (10.0) 10
Total 43 (78.2) 12 (21.8) 55
Young
Adults
(18-27
years)
Number
(percentage) who
defected
Number
(percentage) who
cooperated
Total
Male 28 (90.3) 3 (9.7) 31
Female 16 (100.0) 0 (0.0) 16
Total 44 (93.6) 3 (6.4) 47
Mature
Adults
(28-40 years)
Number
(percentage) who
defected
Number
(percentage) who
cooperated
Total
Male 24 (92.3) 2 (7.7) 26
Female 9 (90.0) 1 (10.0) 10
Total 33 (91.7) 3 (8.3) 36
Older Adults
( 40+ year)
15
Number
(percentage) who
defected
Number
(percentage) who
cooperated
Total
Male 18 (62.1) 11 (37.9) 29
Female 12 (85.7) 2 (14.3) 14
Total 30 (69.8) 13 (30.2) 43
Turning to age, it is noteworthy that cooperation rates varied by stage of life.
Juveniles cooperated more than on average (21.8 per cent). The high rate of
cooperation among teenagers, however, fell away sharply upon attaining
maturity. Only 6.4 per cent of young adults and 8.3 per cent of mature adults
cooperated. After 40 (older adults), however, cooperation rates rapidly
increased to 30.2 per cent. This disparity between younger and older adults is
consistent with the findings of Oberholzer-Gee et al. (2003) who discovered
that adults less than 28 years old on the game show Friend or Foe were far
less ready to cooperate than those older than them (38.7 per cent to 51.6 per
cent).
While List (2004) has previously studied the behavior of 19 year olds in one-
shot and multiple-shot public good games, ours is the first study to measure
cooperation rates among teenagers as young as fifteen in a classic prisoner’s
dilemma game. The rates found are high both relative to those exhibited by
adults under 40 years of age and when one takes into consideration the
extreme context in which the ‘game’ took place. They suggest that differences
in cooperation rates are not simply a reflection of being old or young, but
rather products of the varying social position, roles and attitudes of the
different age groups.
IV. Cooperation
Since the earliest testing of the prisoner’s dilemma in laboratories, the high
rates of cooperation among subjects observed has attracted considerable
16
attention (Roth, 1995). Broadly speaking, three types of explanation for
cooperation, or solutions to the standard prisoner’s dilemma, have been put
forward. The first of these genres relates to features which are either added to,
or alter, the original game, making its subjects more amenable to cooperative
behavior. Among these changes, the most common highlight the infinite
repetition of the game, the imposition of credible and sufficiently large
penalties outside the game to those who defect within it, and the reduction of
the risk of cooperation achieved by ensuring that there is always some
individual benefit to those who cooperate (Dixit et al., 2009; Kümmerli et al.,
2007). The introduction of asymmetry into the game in terms of either the
information players have about their opponents’ nature and payoffs, or the
actual payoffs of the different players, or in the player’s ability to think
strategically can also engender cooperation (Dixit et al., 2009; Kahn &
Murnighan, 2008; Chwe, 2013). None of these circumstances apply to our
scenario. Resisters to the Nazi regime found themselves in a one-shot game,
where no credible external penalty was possible because detection of defection
itself was not possible, where cooperation brought no benefit unless everyone
else cooperated, and where payoffs, knowledge and abilities were not
systematically different.
A second strand of explanation concerns itself with the attitude taken by some
players in certain specific, usually artificial, ‘game’ settings. Knowing, for
example, that they are being observed, players in both experiments and game
shows can ‘play up’ for the audience. They do not behave as they would
normally because they figure that how they perform in the game may have
ramifications outside the game. Some may behave in the way they believe is
expected of them, whereas other may become particularly concerned about
being publically seen as nasty or anti-social and curb their self-interest
accordingly (List, 2006; van den Assem et al., 2012). Context also seemingly
matters here. Stakes that might be regarded as high in everyday life and would
normally be worth defecting for become ‘peanuts’ in other contexts where the
17
prizes that are being played for are even larger (van der Assem et al., 2012).
Neither of these features displayed by some game show participants would
have had much impact on the choice of resisters under interrogation in Nazi
Germany. While many may have wished to have pleased their captors by
defecting, they only did so within the ‘rules of the game’, that is, in return for
a hoped for lighter punishment. They did not alter their behavior in order to
satisfy an external, non-participating audience. No doubt, examples of the ‘big
peanuts’ phenomenon may have taken place in the interrogation room,
although we have not found any in the records. But it is hypothetically
possible. Resisters who, say, in 1938, before being detained, may have
normally betrayed their collaborators in return for a payment of 20,000 RM
(Reichmarks) being secretly made to their relatives, after arrest may well have
spurned such a hypothetical offer while the threat of execution or life
imprisonment remained hanging over their heads. Even if it existed, however,
such phenomena would have had no bearing on a resister’s choice to defect or
not.
The third variety of explanation for cooperation focuses on beliefs held or
thought patterns exhibited by players which enable them to overcome self-
interest. Some are allegedly driven to cooperate by an ethical or moral
imperative. It could be religious in origin, as in the biblical injunction to ‘do
unto others as you would have them do to you’ (Luke 6: 31), or have more
philosophical roots, such as the Kantian Categorical Imperative to ‘take only
such actions as you would like to see become a universal law’ (Dixit &
Nalebuff, 2008). Whatever its origins, it may encourage players to adopt a
form of irrational ‘quasi-magical thinking’ that leads them not only to ignore
their own self-interest, but behave as if their own actions (not to defect in this
case) can somehow influence the independent actions of others to act similarly
(Shafir & Tversky, 1992). As a result, some players can continue to cooperate
even in situations when all the evidence suggests there is little point in so
doing.
18
A related, yet clearly distinct, theme in the literature centers on a player’s
genuine belief that the others in the game will cooperate. When such belief
exists, that player is willing to choose cooperation even though in so doing
they expose themselves to considerable risk of loss. Unlike moral imperatives
or ‘quasi-magical thinking’, such ‘conditional cooperation’ is based on neither
wishfulness nor metaphysical values (Fischbacher et al, 2001; Frey & Meier,
2004; Oberholzer-Gee et al., 2010). Rather, it is grounded in empirical
evidence that the belief is justified. Players look to past experience, character
traits and the words and actions of other players for clues to their
trustworthiness. Good communication with another player, the ability to be
able to look them in the eye and hear their voluntary promises of cooperation
are all factors conducive to the building of trust (Belot, 2010; Sally, 1995).
While it is impossible to determine the extent to which a resister’s choice to
cooperate was influenced by particular thought patterns or moral principles, it
is highly probable that their actions in many cases were conditioned by a
belief that their co-defendants would also cooperate. Such confidence was
shaped by the fact that often the defendants knew each other and shared
common backgrounds, experiences and aspirations. They also believed the
same things and were members of the same communities, organizations and
groups, affiliations that formed key elements of their individual identities.
Identity is an important influence on behavior (Akerlof and Kranton, 2010).
For many resisters, their workplace and membership of political parties,
religious and ethnic organizations, voluntary associations and occupational
classes defined much about who they were and how they behaved. To
challenge one’s very identity by yielding to a Nazi system fundamentally
opposed to everything you stood for and held dear was no doubt a powerful
deterrent for some. Moreover, by defecting, one also betrayed others from
their community, party, or organization and further augmented the
psychological torment, loss of identity and sense of belonging. Although the
degrees to which resisters felt the bind of identity varied, for some, as
19
evidenced by their testimonies, it was deeply held and was assumed to be
similarly held by co-defendants.
V. Results
To explore the determinants of cooperation among resisters charged with high
treason in Nazi Germany, we estimate a probit model around a latent
regression of the form
Cooperation = iX +i
where Cooperation is the resister’s choice to cooperate or not, X is a vector of
personal environmental characteristics related to that resister, i is the
estimated response coefficient vector, and i is the random error term.
In the estimations reported below, two varieties of the dependent variable,
Cooperation, are investigated: (i) the resister’s choice between cooperation
and defection (Cooperation versus Defection), and (ii) the resister’s choice to
defect or not when a co-defendant has defected (Co-defendant Defection
versus Both Defection). The first is just the straightforward choice to defect or
not, while the latter investigates whether defection by co-defendants elicits
different behavior from a resister. In other words, did the actual defection of a
co-defendant make a resister more likely to defect as well? While such a
defection by a co-defendant would not actually be known by the resister, it is
conceivable that a resister may have formed opinions as to the likelihood of a
co-defendant defecting. To the extent that these opinions were based on valid
assessments of the co-defendants themselves, one would expect that they
would closely match the actual pattern of defection observed in the data. If this
were the case, then differences in the determinants of the resister’s choice
between the two versions of Cooperation may be detectable.
20
The vector X captures variables that may influence the choice to cooperate or
not. Variables included in X are listed in Table 7 and encapsulate a variety of
factors related to the resister’s personal history, education, occupation,
employment, beliefs and memberships. Most variables are dichotomous and
equal 1 if the characteristic is present and 0 otherwise. For example, ‘Engaged
or married’ equals 1 if the resister is either married or engaged; 0 if they are
not. A few variables are categorical and are scored in ascending order. Thus,
the resister’s highest educational achievement variable, ‘Education’, is
constructed such that if that achievement was primary school it would equal 1,
vocational or trade school 2, high school 3, and university 4. In addition to the
variables given in Table 7, X also includes the age of the resister at the time of
indictment, the number of co-defendants involved in their case, and dummies
for the early phases of the war (September 1939 to May 1941) and the period
after the invasion of the Soviet Union (June 1941) and the beginning of war on
two fronts.
Table 7. Personal and environmental characteristics of resisters
Number Percentage
Personal History
Male 131 72.4
Female 50 27.6
German1 158 87.3
‘Mixed blood’: not regarded as of full German
ethnicity by the Nazis2
16 8.8
Foreigner &/or stateless 7 3.9
Spent time Outside the Reich3 21 11.6
Engaged or married 72 39.8
Experienced chronic health problems 11 6.1
Family member(s) persecuted by the Nazis 7 3.9
Juvenile or young adult with at least one parent
deceased
13 7.1
Parents divorced 6 3.3
Close family member(s) killed in war 12 6.6
Immediate family member(s) engaged in anti-regime 65 35.9
21
activities
No adult involvement in their act of resistance 21 11.6
Previous charges 37 20.4
Served in WWI 22 12.2
Served in WWII 14 7.7
Highest Educational Achievement
University 7 3.9
High school 47 26.0
Vocational or trade school 67 37.0
Primary 60 33.1
Occupation
Student 6 3.3
No particular occupation 13 7.2
Blue collar 120 66.3
White collar 26 14.4
Professional 11 6.1
Business or property owner 5 2.8
Employment
Employed 130 71.8
Unemployed 8 4.4
Not in the labor force 43 23.8
Beliefs and Memberships
Supporter of Austrian independence 123 68.0
Denied entry or never joined Hitler Youth or BDM4 15 8.3
Expelled from Hitler Youth or BDM (prior to charges
being laid)
6 3.3
Left Hitler Youth of BDM of own accord 12 6.6
Member of youth street gang 10 5.5
Member of a Communist organization 60 33.2
Member of a Social Democratic organization 27 14.9
Member of the Nazi party 8 4.4
Voluntary member of a non-political and non-
religious organization
23 12.7
Strong religious affiliation 43 23.8
Skilled laborer5 93 51.4
Engaged in anti-war activities 138 76.2 1. ‘German’ includes Austrians. Austria became part of Greater Germany after the Anschluss of March 1938.
2. The term, ‘mixed blood’ or Mischlinge in German, typically referred to individuals with at least one parent or
grandparent of Jewish descent.
3. This figure excludes resisters who had spent time outside Germany only as part of their military service.
4. Bund Deutscher Mädel (League of German Girls).
5. A ‘skilled laborer’ is someone who had completed or was doing an apprenticeship or some formal vocational
training.
22
The first two columns of Table 8 relate to the determinants of the simple
choice between cooperation and defection. They show the statistical
significance of eight variables, the marginal effects of which are given in
square brackets.9 One of these significant variables is age. Once allowance is
made for other influences, which are discussed shortly, age remains highly
significant. For each year of age, the probability of defection declined by 1.6
per cent, a finding which among other things suggests that the lower rates of
cooperation observed among young and mature adults are probably better
explained by broader characteristics of these age groups’ experiences rather
than their age per se.10
Table 8. Binary Probit Models of Cooperation and Defection
Cooperation
vs. Defection
Cooperation
vs. Defection
Co-
defendant
Defection
vs. Both
Defection
Co-
defendant
Defection
vs. Both
Defection
Age -0.056
(0.00)***
[-0.016]
-0.053
(0.00)***
[-0.016]
-0.068
(0.00)***
[-0.019]
-0.064
(0.00)***
[-0.018]
Education -0.366
(0.05)**
[-0.104]
-0.414
(0.01)***
[-0.117]
-0.417
(0.04)**
[-0.116]
-0.414
(0.02)**
[-0.115]
Member of
Social
Democratic
organization
1.544
(0.02)**
[0.438]
1.465
(0.02)**
[0.415]
1.620
(0.02)**
[0.450]
1.530
(0.03)**
[0.425]
Anti-war
activist
-0.888
(0.05)**
[-0.252]
-0.782
(0.07)*
[-0.222]
-1.289
(0.03)**
[-0.357]
-1.239
(0.03)**
[-0.344]
Skilled Laborer -0.830 -0.902 -0.755 -0.823
9 Variables not reported in Table 8 or discussed in the text were found to be
insignificant in all specifications or capable of being estimated. For the
insignificant variables, their inclusion in the models does not impact the
significance of the other variables in Table 8 indicating robustness in the
results. 10
Modeling age non-linearly proved insignificant.
23
(0.01)***
[-0.235]
(0.01)***
[-0.256]
(0.05)**
[-0.209]
(0.02)**
[-0.228]
Member of
Non-political or
religious
organization
-0.988
(0.01)***
[-0.280]
-0.912
(0.02)**
[-0.258]
-1.356
(0.00)***
[-0.376]
-1.314
(0.00)***
[-0.365]
No Adult co-
defendant
-1.292
(0.01)***
[-0.366]
-1.608
(0.00)***
[-0.456]
-1.188
(0.06)*
[-0.330]
-1.324
(0.01)***
[-0.368]
Juvenile or
young adult
with at least one
parent deceased
-0.995
(0.05)**
[-0.282]
-1.038
(0.04)**
[-0.294]
-1.158
(0.05)**
[-0.321]
-1.177
(0.04)**
[-0.327]
Occupation 0.050
(0.75)
[-0.235]
0.134
(0.43)
[0.037]
Male -0.304
(0.47)
[-0.086]
-0.269
(0.55)
[-0.075]
Number of co-
defendants
0.043
(0.41)
[0.012]
0.005
(0.94)
[0.001]
Member of
Communist
organization
-0.064
(0.86)
[-0.018]
-0.036
(0.93)
[-0.010]
Strong religious
affiliation
-0.199
(0.59)
[-0.056]
-0.067
(0.88)
[-0.019]
McFadden R2 0.355 0.348 0.380 0.374
LR test 58.905
(0.00)***
57.603
(0.00)***
52.958
(0.00)***
52.124
(0.00)***
Prediction
Defection
143/150
(p>0.5)
137/150
(p>0.6)
145/150
(p>0.5)
139/150
(p>0.6)
146/149
(p>0.5)
144/149
(p>0.6)
144/149
(p>0.5)
144/149
(p>0.6)
Prediction
Cooperation
16/31
(p<0.5)
19/31
(p<0.6)
15/31
(p<0.5)
19/31
(p<0.6)
13/24
(p<0.5)
14/24
(p<0.6)
12/24
(p<0.5)
14/24
(p<0.6) Notes: p-values are in parenthesis. Marginal effects are given in square brackets. * denotes significance
at the 10 per cent level, ** at the 5 per cent, *** at the 1 per cent.
24
Nor does gender appear to have been a key determinant of cooperation. The
explanation for the relatively low cooperation rates of female resisters thus
appears to lie, not in their gender, but ability to acquire other characteristics
that did deter defection. It is also noteworthy that while the coefficient on the
number of co-defendants in a case has the right sign (positive), it is
statistically insignificant. On the whole, therefore, the choice made by resisters
does not appear to have been influenced by the existence of more or less co-
defendants, even though, ceteris paribus, more co-defendants increased the
likelihood of a defection occurring within a case and, hence, the personal risk
of pursuing a cooperative strategy (since such cooperation could only bring
benefits if all cooperated). Other factors seemingly pressed more heavily in
their deliberations.
Of these, education appears to have been central. Defection was inversely
related to the resister’s highest level of educational attainment. For each ‘step’
in their attainment (from primary through tertiary), the probability of defection
decreased by about 10 per cent. Two factors lie behind this finding. Better
educated resisters were, firstly, less inclined to capitulate to the intellectually
bereft Nazi view of the world and, second, less likely to be duped by Gestapo
interrogation techniques.
Table 8 also provides statistical evidence that being a member of a social
democratic organization increased your chances of becoming a defector by as
much as 41.5 per cent. This result needs to be interpreted within its proper
context. Most resisters charged with high treason were individuals deeply
committed to a cause that was based upon a strong, often dogmatically
interpreted, ideological, theological or philosophical value system
fundamentally in conflict with the Nazis’ (e.g. Communism, Catholicism,
Mormonism, and Pacifism). Many, of course, chose to defect anyway, but,
from what we know about these movements and their belief structures, the
idea that such a course of action represented a betrayal of the cause must
25
surely have weighed heavily in the mind (Benz et al., 1996; Steinbach &
Tuchel, 2000, 2004). The significance of anti-war activism in the estimations –
a characteristic which reduced defection by around 25 per cent – and the
similarly correct, though statistically insignificant, negative signs on the
coefficients for involvement in communist and religious organizations are
consistent with this notion. By contrast, involvement in social democratic
politics carried less ideological or theological baggage and less party or church
discipline. Social democracy was more tolerant of deviation and more flexible
in approach (Steinbach & Tuchel, 2000, 2004). As a result, defection brought
with it potentially less stigma. Members of social democratic organizations,
while still adamantly opposed to Hitler and Nazism, were intellectually and
politically freer to evaluate their situation from a pragmatic perspective.
Political or religious causes were, of course, not the only affiliations that could
impinge on the decision to cooperate. Skilled workers were among the most
heavily unionized, organized and cohesive group in twentieth-century
Germany. Their training placed them apart from and above other sections of
the workforce and encouraged a sense of camaraderie with fellow skilled
workers.11
It was a connection that saw many collaborate in acts of resistance
against a regime which had abolished their unions and sought to constrain
their independence and collective strength within the Nazi-run German Labor
Front (Steinbach & Tuchel, 1990, 2000, 2004; Peukert, 1991). Resisters who
were skilled laborers were, as a consequence, about 25 per cent less likely to
defect.
Similarly, resisters who were members of voluntary non-political, non-
religious organizations, such as the Red Cross, Boy Scouts, hiking societies,
gymnastic clubs, and sporting associations exhibited a similar inclination
11
It is noteworthy that levels of occupation (i.e. blue collar, white collar,
professional, business and property owners) had no significant statistical
impact on cooperation. It was the shared skills of artisans and their
organizations that bound.
26
toward cooperation. Often taken as measures of social capital, participation in
these organizations, which proliferated in interwar Germany (Satyanath et al.,
2013), also fostered trust between members and a sense of community
(Putnam, 2000; Durlauf & Fafchamps, 2004; Field, 2003), attributes which
together appear to have engendered in some a belief that mutual cooperation
was plausible. In fact, involvement in these organizations reduced the
likelihood of defection by about 25 per cent. This is an interesting finding, for
it emphasizes the importance of social capital and community in building trust
and cooperation. Even in these most horrendous of circumstances, these could
make a significant difference. Consider the case of a skilled laborer active in,
say, the Red Cross. Our estimations indicate that such an individual would
have been around 50 per cent more likely to cooperate. Being part of the
community and playing an active role in civil society in some circumstances
galvanizes cooperation.12
Another distinct group within the experiment were resisters aged between 15
and 17. This group had a strong sense of identity that overlapped, yet was
separate from, those of their adult co-resisters. What distinguished juvenile
from adult resistance were the degree of independent, small group decision
making involved; its atomistic nature; its frequent lack of strong adult
supervision; and the absence of any attempt to fit actions into a broader
strategy for change (Geerling et al., 2013). Juveniles also evidently felt securer
with each other than adults. Not only were cooperation rates higher among
juveniles than for any other age group except that of the over 40s, but
cooperation was more forthcoming when all the other defendants in a case
were also juveniles. When that was the case, the likelihood of defection fell by
as much as 45 per cent.
12
Such cooperation, of course, need not always lead to beneficial outcomes.
Satyanath et al. (2013) argue that the development of social capital in Weimar
Germany facilitated the rise of the Nazi party.
27
While the bonds of youth may have created solidarity among juveniles, it
appears not to have come at the expense of other attachments, least of all those
of the family. Table 8 reveals that juveniles and young adults whose parents
were both alive at the time of interrogation were about 28 per cent more likely
to defect. It was commonplace for Gestapo interrogators to threaten the well-
being of family members. Unsurprisingly, teenagers and young adults, most of
whom still lived at home and cared about their parents’ welfare, were
particularly vulnerable targets for such intimidation.
Columns 3 and 4 of Table 8 provide an estimate of a model of choice where
one of the other co-defendants defected. The most striking aspect of this
model is its very close similarity, both in terms of significant variables and
marginal effects, with the plain defection versus cooperation model discussed
above. Whether a co-defendant defected or not seemingly had little bearing on
the process used by resisters to make their choice. This might have been
because resisters did not take beliefs about what other defendants might do
into consideration or, alternatively, because whatever beliefs they might have
formed on the basis of association did not accord with reality. Either way,
these findings suggest that in a one-shot prisoners’ dilemma like this, where
knowledge of which types of players had defected in the past is unknown,
conditional cooperation merely based on previous rounds of the game played
by different players is not likely to be an important consideration. This is not
to say, of course, that resisters could not have formed systematic beliefs about
the probable actions of other resisters with certain characteristics, but, given
the context, such beliefs, if they existed, could not have been formed on the
basis of knowledge about whether specific resisters or others like them had
previously defected when interrogated by the Gestapo. Unfortunately, with
only 29 cases in the database, more than half of which have at least five
defendants, it is not possible to test rigorously whether one resister’s decision
could be influenced by a specific characteristic of another.
28
VI. Concluding Comments
To the best of our knowledge, this study is the first to analyze cooperative
behavior within a real-world, one-shot, high-stakes prisoner’s dilemma that
conforms closely to the story so often related in textbooks. The ‘prisoners’ in
question were individuals arrested and charged with high treason in Nazi
Germany between 1933 and 1945. Investigation of this natural experiment
reveals four major insights.
First, it confirms that the prisoner’s dilemma is a powerful tool for analyzing
real-world situations. The theoretical prediction that defection is the dominant
strategy of this game holds even when, as in this case, many of the subjects
subscribed to strong ideological or spiritual belief structures: the vast majority
of resisters did in fact defect. However, as in experiments and on game shows,
a non-negligible share – some 17.1 per cent – of resisters opted to cooperate,
even when faced with the possibilities of torture and execution.
Second, our findings suggest that the size of what is at stake can impact the
extent of social preferences exhibited. Our natural experiment has the highest
possible stake: one’s life and liberty. While a surprisingly large share of
resisters still chose not to defect, the observed cooperation rate was well below
that reported in previous literature on the prisoner’s dilemma. These results
indicate that, perhaps, the stakes tested in experiments and offered on game
shows have not been high enough or significantly different from each other (or
indeed both) to isolate the effect clearly. Moreover, we suspect that the
artificial contexts, in which most of these experiments typically take place,
impact players’ behavior as well.
Third, the paper finds evidence that age, gender and education influence
cooperation rates, though not in as straightforward a way as usually claimed.
Age and gender are important, but not in isolation. They need to be read in
context and in conjunction with other factors. We find, for example, that
29
female resisters defected at a greater rate than male, not because of their
gender per se, but because their place in German society at the time denied
them the opportunities to acquire the characteristics most conducive to
cooperation. In the 1930s and 40s, few women received more than basic
schooling, few were trained to become skilled laborers, and few were formally
involved in the major political and religious movements of the day (Wickert,
1995, 1996).
Fourth, this natural experiment has revealed the important roles that beliefs,
identity and community can have on overcoming Nash play. While the
importance of each might vary by context – political beliefs, for example, may
have little impact in the laboratory where all that is being played for is a few
dollars – they arguably have greater significance in many real-world situations
where consequences endure and the social implications of wide-scale
defection are problematic. Our findings suggest that investing in social capital
and encouraging deeper engagement with civil society may be two ways in
which communities can mitigate some of the consequences of the prisoner’s
dilemma.
REFERENCES
Akerlof, George A., and Rachel E. Kranton. 2010. Identity Economics: How
our Identities Shape our Work, Wages, and Well-Being. Princeton: Princeton
University Press.
Belot, Michèle, V. Bhaskar, and Jeroen van de Ven. 2010. “Promises and
Cooperation: Evidence from a TV Game Show.” Journal of Economic
Behavior & Organization 73: 396-405.
30
Benz, Wolfgang and Walter H. Pehle, eds. 1996. Encyclopaedia of German
Resistance to the Nazi Movement. New York: Continuum International
Publishing Group.
Birkeland, Sigbjørn, d.y., Alexander W. Cappelen, Erik. Ø. Sørensen, and
Berti Tungodden. 2011. “Immoral Criminals? An Experimental Study of
Social Preferences among Prisoners,” Department of Economics Discussion
Papers, Norwegian School of Economics, SAM 15.
Bundesarchiv, Case Files of the Volksgerichtshof . Berlin: unpublished, 1934-
1945.
Cameron, Lisa A. 1999. “Raising the Stakes in the Ultimatum Game:
Experimental Evidence from Indonesia.” Economic Inquiry 37 (1): 47-59.
Carpenter, Jeffery, Eric Verhoogen, and Stephen Burks. 2005. “The Effects of
Stakes in Distribution Experiments,” Economic Letters 86 (3): 393-398.
Churma, Thorsten, Christoph Engel, Markus Engelereth, and Thomas Pitz.
2010. “At the Mercy of the Prisoner Next Door - Using an Experimental
Measure of Selfishness as a Criminological Tool.” Max Planck Institute for
Research on Collective Goods, Bonn, 27.
Chwe, Michael Suk-Young. 2013. Jane Austen, Game Theorist. Princeton:
Princeton University Press.
Dixit, Avinash K, and Barry J. Nalebuff. 2008. The Art of Strategy: A Game
Theorist’s Guide to Success in Business and Life. New York: W. W. Norton.
Dixit, Avinash, Susan Skeath, and David Reiley. 2009. Games of Strategy.
New York: W. W. Norton.
Dokumentation Österreichischen Widerstandes, Case Files of the
Volksgerichtshof. Vienna: unpublished, 1934-1945.
31
Durlauf, Steven N., and Marcel Fafchamps. 2004. “Social Capital,” NBER
Working Paper 10485.
Field, John. 2003. Social Capital. London: Routledge.
Fischbacher, Urs, Simon Gächter, and Ernst Fehr. 2001. “Are People
Conditionally Cooperative? Evidence from a Public Goods Experiment.”
Economic Letters 71 (3): 397-404.
Frey, Bruno S., and Stephan Meier. 2004. “Social Comparisons and Pro-Social
Behavior: Testing ‘Conditional Cooperation’ in a Field Experiment.”
American Economic Review 94 (5): 1717-1722.
Geerling, Wayne, Gary B. Magee, and Robert Brooks. 2013. “Faces of
Opposition: Juvenile Resistance, High Treason and the People’s Court in Nazi
Germany.” Journal of Interdisciplinary History 44 (2): 209-234.
Kahn, Lawrence M. and J. Keith Murnighan. 2008. “Payoff Uncertainty and
Cooperation in Finitely-repeated Prisoner's Dilemma Games.” in Charles R.
Plott and Vernon L. Smith, eds. The Handbook of Experimental Economics
Results, Volume 1. Amsterdam: North-Holland, 2008: 598-606.
Kahneman, Daniel, and Amos Tversky. 1979. “Prospect Theory: An Analysis
of Decision under Risk.” Econometrica 47 (2): 263-291.
Kocher, Martin G., Peter Martinsson, and Martine Visser. 2008. “Does Stake
Size Matter for Cooperation and Punishment?” Economic Letters 99 (3): 508-
511.
Khadjavi, Menusch, and Andreas Lange. 2013. “Prisoners and their
Dilemmas.” Journal of Economic Behavior and Organization 92: 163-175.
Kuhn, Steven. 2009. “Prisoner’s Dilemma.” in Edward N. Zalta ed., The
Stanford Encyclopedia of Philosophy. Spring 2009 Edition.
http://plato.stanford.edu/archives/spr2009/entries/prisoner-dilemma/.
32
Kümmerli, Rolf, Caroline Colliard, Nicolas Fiechter, Blaise Petitpierre,
Lavien Russier, and Laurent Keller. 2007. “Human Cooperation in Social
Dilemmas: Comparing the Snowdrift Game with the Prisoner’s Dilemma.”
Proceedings of the Royal Society B 274: 2965-2970.
Levitt, Steven D., and John A. List. 2008. “Homo Economicus Evolves.”
Science 319: 909-910.
List, John A. 2006. “Friend or Foe? A Natural Experiment of the Prisoner’s
Dilemma.” Review of Economics and Statistics 88 (3): 463-471.
List, John A. 2004. “Young, Selfish and Male: Field Evidence of Social
Preferences.” Economic Journal 114: 121-149.
Oberholzer-Gee, Felix, Joel Waldfogel, and Matthew W. White. 2010.
“Friend or Foe? Cooperation and Learning in High-Stakes Games.’ Review of
Economics and Statistics 92 (1): 179-187.
Oberholzer-Gee, Felix, Joel Waldfogel, and Matthew W. White. 2003. “Social
Learning and Coordination in High-Stakes Games: Evidence from Friend or
Foe.” NBER working paper no. 9805.
Peukert, Detlev. 1991. “Working-Class Resistance: Problems and Options.” In
David C. Large ed. Contending with Hitler: Varieties of German Resistance in
the Third Reich. Cambridge: Cambridge University Press: 35-48.
Putnam, Robert D. 2000. Bowling Alone: The Collapse and Revival of
American Community. New York: Simon & Schuster.
Roth, Alvin E. 1995. “Introduction to Experimental Economics,” in John H.
Kagel and Alvin E, Roth, eds. The Handbook of Experimental Economics.
Princeton: Princeton University Press.
33
Satyanath, Shanker, Nico Voigtlaender, and Hans-Joachim Voth. 2013.
“Bowling for Fascism: Social Capital and the Rise of the Nazi Party in
Weimar Germany, 1919-1933.” NBER Working Paper 19201.
Sally, David. 1995. “Conversation and Cooperation in Social Dilemmas: A
Meta-Analysis of Experiments from 1958 to 1992.” Rationality and Society 7
(1): 58-92.
Shafir, Eldar, and Amos Tversky. 1992. “Thinking through Uncertainty:
Nonconsequential Reasoning and Choice.” Cognitive Psychology 24: 449-474.
Slonim, Robert, and Alvin E. Roth. 1998. “Learning in High Stakes
Ultimatum Games: An Experiment in the Slovak Republic.” Econometrica 66
(3): 569-596.
Steinbach Peter, and Johannes Tuchel, eds. 2004. Widerstand gegen die
nationalsozialistische Diktatur 1933–1945. Berlin: Lukas.
Steinbach Peter, and Johannes Tuchel, eds. 2000. Widerstand in Deutschland
1933-1945. Munich: Beck.
Steinbach Peter, and Johannes Tuchel, eds. 1998. Lexikon des Widerstandes
1933-1945. Munich: Beck.
Steinbach Peter, and Johannes Tuchel, 1990. “Widerstand aus der
Arbeiterbewegung bis 1939.” in Peter Steinbach and Johannes Tuchel, eds.
Gedenkstätte Deutscher Widerstand. Katalog zur Sonderausstellung der
Gedenkstätte Deutscher Widerstand in Zusammenarbeit mit der Neuen
Richtervereinigung. Berlin: 167-184.
van den Assem, Martijn J., Dennie van Dolder, and Richard H. Thaler. 2012.
“Split or Steal? Cooperative Behavior When the Stakes Are Large.”
Management Science 58 (1): 2-20.
34
Wickert, Christl, ed. 1995. Frauen gegen die Diktatur: Widerstand und
Verfolgung im nationalsozialistischen Deutschland. Berlin: Hentrich &
Hentrich.
Wickert, Christl, 1996. “Women between Dissent and Resistance,” in
Wolfgang Benz and Walter H. Pehle, eds. Encyclopaedia of German
Resistance to the Nazi Movement. New York: Continuum International
Publishing Group: 101-113.
Zarusky, Jürgen, and Hartmut Mehringer, eds. 1998. Erschließungsband zur
Mikrofiche-Edition, Widerstand als Hochverrat: 1933-1945: Die Verfahren
gegen deutsche Reichsangehörige vor dem Reichsgericht, dem
Volksgerichtshof und dem Reichskriegsgericht. Munich: K. G. Saur.