Terms
Birth rate (or crude birth rate): The annual number of births per 1,000 total population.
Doubling time: The number of years required for the population of an area to double its present size, given the current rate of population growth. Population doubling time is useful to demonstrate the long-term effect of a growth rate, but should not be used to project population size. Many more-developed countries have very low growth rates. But these countries are not expected to ever double again. Most, in fact, likely have population declines in their future. Many less-developed countries have high growth rates that are associated with short doubling times, but are expected to grow more slowly as birth rates are expected to continue to decline.
Growth rate: The number of persons added to (or subtracted from) a population in a year due to natural increase and net migration; expressed as a percentage of the population at the beginning of the time period.
Less developed countries: Less developed countries include all countries in Africa, Asia (excluding Japan), and Latin America and the Caribbean, and the regions of Melanesia, Micronesia, and Polynesia.
More developed countries: More developed countries include all countries in Europe, North America, Australia, New Zealand, and Japan.