Human population planning is the practice of intentionally controlling the growth rate of a human population. The practice, traditionally referred to as population control, had historically been implemented mainly with the goal of increasing population growth, though from the 1950s to the 1980s, concerns about overpopulation and its effects on poverty, the environment and political stability led to efforts to reduce population growth rates in many countries. More recently, however, several countries such as China, Japan, South Korea, Russia, Iran, Italy, Spain, Finland, Hungary and Estonia have begun efforts to boost birth rates once again, generally as a response to looming demographic crises. While population planning can involve measures that improve people's lives by giving them greater control of their reproduction, a few programs, such as the Chinese government's "one-child policy and two-child policy", have employed coercive measures. Types Three types of population planning policies pursued by governments can be identified: Increasing or decreasing the overall population growth rate. Increasing or decreasing the relative population growth of a subgroup of people, such as those of high or low intelligence or those with special abilities or disabilities. Policies that aim to boost relative growth rates are known as positive eugenics; those that aim to reduce relative growth rates are known as negative eugenics. Attempts to ensure that all population groups of a certain type (e.g. all social classes within a society) have the same average rate of population growth. Methods While a specific population planning practice may be legal/mandated in one country, it may be illegal or restricted in another, indicative of the controversy surrounding this topic. Increasing population growth Population policies that are intended to increase a population or subpopulation growth rates may use practices such as: Higher taxation of married couples who have no, or too few, children Politicians imploring the populace to have bigger families Tax breaks and subsidies for families with children Loosening of immigration restrictions, and/or mass recruitment of foreign workers by the government History Ancient times through Middle Ages A number of ancient writers have reflected on the issue of population. At about 300 BC, the Indian political philosopher Chanakya (c. 350-283 BC) considered population a source of political, economic, and military strength. Though a given region can house too many or too few people, he considered the latter possibility to be the greater evil. Chanakya favored the remarriage of widows (which at the time