PIP: China's birthrate increased from 18 births/1000 population in 1985 to 21/1000 in 1986, after a decade of steady decline. In 1971, to avoid a projected population of 2.4 billion by 2050, Chinese leaders launched the "later-longer-fewer" campaign. Men and women were encouraged to postpone marriage until their mid- to late-20s, to allow 4 years between pregnancies, and to limit their families to 2 children. The standards were slightly more lenient in the rural areas. Together, the campaign was responsible for a reduction in the total fertility rate from 5.9 births/woman in 1970 to 2.7 births in 1979. Yet, due to the age structure of the population, with 39% of Chinese under age 15, even replacement-level fertility was bound to generate growth for decades. Consequently, in 1979, the post-Mao leadership inaugurated the "1-child" policy, a program designed to limit the Chinese population to 1.2 billion by 2000. Family planning has become a state sanctioned and monitored activity. The policy is implemented via public education, persuasion, peer pressure, and a series of incentives and penalties. In this context, the question arises as to what caused China's birthrate to rise. A major factor is the effect of the country's youth-dominated age structure. Following the Great Leap Forward (1958-60) and the prolonged accompanying famine, the birthrate increased markedly as couples conceived the children they had postponed. These baby boomers, born from 1962-64, now are having their own babies. About 1/3 of the 1986 increase in births may be accounted for by the ripple effect of this relatively large cohort finally reaching reproductive age. Further, the age of 1st reproduction has declined recently in response to the Marriage Law of 1980, which lowers the legal marriage age. Another influence has been a gradual yet significant relaxation in some of the basic tenets of the 1-child policy. In 1984, the government reaffirmed the critical importance of family planning but increased the number of exceptions to the 1-child rule.