POPULATION DYNAMICS

Is it getting crowded in here?

Job Available

Washing glassware in the Chemistry Lab.

1 hour per day for 30 days. Pay is either:

A - $10,000/day, or B - $.01 for the first day, and each

subsequent day’s pay is double the previous day.

Option A

$10,000 per day for 30 days is a total of $300,000.

Option BDay Pay ($)

1 .01

2 .02

3 .04

4 .08

5 .16

Week 1 Pay .31

6 .32

7 .64

8 1.28

9 2.56

10 5.12

Week 2 Pay 9.92

Total 10.23

Option B (continued)11 10.24

12 20.48

13 40.96

14 81.92

15 163.84

Week 3 Pay 317.44

Total 327.67

16 327.68

17 655.36

18 1,310.72

19 2,621.44

20 5,242.88

Week 4 Pay 10,158.08

Total 10,485.75

Option B (aren’t we done yet?)

21 10,485.76

22 20,971.52

23 41,943.04

24 83,886.08

25 167,772.16

Week 5 Pay 335,058.56

Total 335,544.31

26 335,544.32

27 671,088.64

28 1,342,177.28

29 2,684,354.56

30 5,368,709.12

Week 6 Pay 10,401,873.92

Total 10,737,418.23

Why is that so hard to grasp? We tend to think in linear terms. Work for 8

hours at $10/hr and you will be paid $80. Linear growth is expressed as a straight line

(assuming you have labeled your axes properly).

Exponential growth Exponential growth starts off slowly, but

begins to accelerate in amount of growth. The rate of growth is constant. Exponential growth is represented by a “J

curve”.

Why is this important?

The human population eclipsed 6 billion in the recent past.

The rate of growth has not appreciably changed.

The amount of growth is accelerating.

We will need to feed, house, clothe, and care for many more people in the coming years.

The rate of growth is highest in poor countries.

World Population Math

Expressed as b – d = r In this equation, r represents the rate

of growth. Demographics in this area are always

expressed as #/1000.

Area Population Math

(b + i) – (d + e) = r The variables i and e account for

movement of people in and out of an area.

Again, the rate of growth is expressed as r.

Rule of 72

If r is converted to a percentage, then the doubling time (DT) for a population can be estimated by dividing 72 by r.

Always convert the demographic number to a percent by moving the decimal point one place to the left.

A population will double in 36 years with a rate of growth of 2/1000 (2%).

Population Density

Country Population (2011

est.)

Land Area

Density(#/sq. mi.)

Household Size

Household Income

Growth Rate

Bangladesh 151,435,000

56,977 2658 5.3 $1,477 2.13%

Canada 34,615,000 3,849,674

9 2.6 $47,413 0.33%

China 1,339,724,000

3,696,100

362 3.4 $1,876 -0.43%

India 1,210,193,000

1,222,559

990 5.6 $2,307 1.59%

Japan 127,950,000

145,884 877 2.3 $61,120 0.16%

Monaco 35,000 0.75 46,667 2.2 $278,259 0.64%Russia 142,914,00

06,592,80

022 2.8 $1,820 -0.67%

United States

312,417,001

3,675,031

85 2.5 $67,228 0.6%

Replacement Level Fertility Estimated as 2.1 children per couple

in developed nations and 2.5 children in developing nations.

If 10 couples (20 people) have a total of 21 children (2.1 children/couple), this population would stay relatively stable in size.

This number accounts for the number of children who will die prior to reproducing.

Age Structure Diagrams

Used to represent age distribution and future trends.

Population controls in China Couples are encouraged to pledge to

having only one child. Couples who make and keep this

pledge get: Extra food, larger pensions, better housing, free

medical care, and salary bonuses. Their children get:

Free school tuition, preferential treatment in employment Couples who violate this policy lose any

and all privileges.

Population Trends in Baltimore

Year Population Change1940 859,1001950 949,708 + 10.5%1960 939,024 - 1.1%1970 905,759 - 3.5%1980 786,775 - 13.1%1990 736,014 - 6.5%2000 651,154 - 11.5%2010 620,961 - 4.6%

Raw Population Size vs. Number of Tax-paying Households While the population in Baltimore has

continued to decline, the number of tax-paying households “bottomed out” in 2003 and has been steadily rising.

Why? Single adults and couples without

children have moved into the city while families have continued to leave.

Life Skills 101

Gross Annual Salary$50,000.00

Taxes (@ 35%)$17,500.00

Net Annual Pay$35,000.00

Net Monthly Pay $ 2708.33

Can you live on this?

Monthly Expenses Rent $700.00 Phone (home & cell w/data plan)

$100.00 Groceries $200.00 Car Payment $350.00 Car Insurance $150.00 Gasoline $100.00 Furniture $400.00 Clothes $200.00 Entertainment $400.00 Cable Television & Internet $100.00 Total $2700.00 What’s Left? $8.33

How to Amass Wealth

Pay yourself FIRST!! Determine a monthly budget AFTER

putting away a set amount in an investment vehicle.

Always put away your monthly savings.

The Rule of 72 works for investments as it does for populations.

Debt can also accrue quickly, according to the Rule of 72.

Investment Vehicles Vehicle APR Insured? Checking Account0 - <1% Yes (FDIC/FSLIC)1

Savings Account 1 – 2% Yes (FDIC/FSLIC)1

Certificate of Deposit 2 – 4%2 Yes (FDIC/FSLIC)1

Bonds 3 – 6% Yes (FDIC/FSLIC)1

Mutual Fund 6 – 9%3 No Money Market 6 – 9%3 No Stocks ? No

1 – Federal Deposit Insurance Corporation/Federal Savings and Loan Insurance Corporation. 2 – Varies with amount invested and term of investment. 3 – Historical average (future returns unpredictable).

Debt Acquisition

Debit Card Tied to your Checking Account

Charge Card Balance must be paid monthly

Credit Card Essentially a loan, interest rate determined by Credit Rating

Loans and Mortgages Interest Rate determined by Credit Rating

Credit Your Credit Rating is a statement of

confidence in your ability and willingness to pay back a loan.

Three Credit agencies gather your financial information and assign a number to you.

A high number is desirable. Creditors frequently consult this report

and adjust interest rates accordingly. Scores go up like a feather and down like

a rock.