post 33

sorry I haven't been blogging in a while, didn't feel like doing it, but I'm back.

push forces

• unemployment or underemployment
• religious or ethnic persecution

pull forces

• better economic opportunity
• better health services
• religious freedom
• political freedom

tfr (total fertility rate)

• average number of children born per women
• for a population to remain the same, the total fertility rate must be 2.1

population pyramids

• we use them to analyze growth, decline, etc in cities or areas

three basic shapes of graphs

• Christmas tree
• the box
• the cup