The world’s population is about 4 billion, twice what it was in 1926, four times what it was in 1866, and half what it will probably be in 2011. This alarming and apparently inexorable increase disguises the one hopeful sign among the statistics: the beginning of a slowdown in the rate of growth of world population. But most or the 200,000 extra people that swell the world’s numbers daily are born in less-developed countries. Many developed countries have recently liberalised their abortion laws. In Britain the number of abortions rose from 82,000 in 1970 to 116,000 in 1975; in Poland and the Soviet Union abortion is available on demand (although if the people prefer to grin and bear children their may get a medal for doing so). In many developed countries an increasing number of women are going out to work and, though they may be married, they tend to postpone or limit child-bearing.