Family planning allows couples to determine the number and spacing of their children.
Birth control usually means any method used to reduce births.
The major categories of birth control techniques
(1) avoidance of sex during fertile periods (for example, celibacy or the use of changes in body temperature or cervical mucus to judge when ovulation will occur)
(2) mechanical barriers that prevent contact between sperm and egg (for example, condoms, spermicides, diaphragms, cervical caps, and vaginal sponges)
(3) surgical methods that prevent release of sperm or egg (for example, tubal ligations in females and vasectomies in males)
(4) hormone-like chemicals that prevent maturation or release of sperm or eggs or that prevent embryo implantation in the uterus (for example, estrogen plus progesterone, or progesterone alone, for females; gossypol for males)
(5) physical barriers to implantation (for example, intrauterine devices)
1. About how many years of human existence passed before the world population reached its first billion? What factors restricted population before that time, and what factors contributed to growth after that point?
2. Describe the pattern of human population growth over the past 200 years. What is the shape of the growth curve (recall chapter 3)?
3. Define ecological footprint. Why is it helpful, but why might it also be inaccurate?
4. Why do some economists consider human resources more important than natural resources in determining a country’s future?