1992, Laumann found that circumcised men were more likely to report masturbating at least once a month.) As hospitals proliferated in urban areas, childbirth, at least among the upper and middle classes, was increasingly under the care of physicians in hospitals rather than with midwives in the home. It has been suggested that once a critical mass of infants were being circumcised in the hospital, circumcision became a class marker of those wealthy enough to afford a hospital birth. During the same time period, circumcision was becoming easier to perform. William Stewart Halsted's 1885 discovery of hypodermic cocaine as a local anaesthetic made it easier for doctors without expertise in the use of chloroform and other general anaesthetics to perform minor surgeries. Also, several mechanically aided circumcision techniques, forerunners of modern clamp-based circumcision methods, were first published in the medical literature of the 1890s, allowing surgeons to perform circumcisions more safely and successfully. Born in the United Kingdom during the late 19th century, John Maynard Keynes and his brother Geoffrey, were both circumcised in boyhood due to parents' concern about their masturbatory habits. Some mainstream pediatric manuals continued to recommend circumcision as a deterrent against masturbation until the 1950s. Spread and decline Infant circumcision was taken up in the United Kingdom, the United States, Australia, New Zealand, and the English-speaking parts of Canada and South Africa. Although it is difficult to determine historical circumcision rates, one estimate of infant circumcision rates in the United States holds that 30% of newborn American boys were being circumcised in 1900, 55% in 1925, 72% in 1950, 85% in 1975 and 60% in 2000. In South Korea, circumcision was largely unknown before the establishment of the United States trusteeship in 1945 and the spread of American influence. More than 90% of South Korean high school boys are now circumcised at an average age of 12 years, which makes South Korea a unique case. However circumcision rates are now declining in South Korea. Decline in circumcision in the English-speaking world began in the postwar period. The British paediatrician Douglas Gairdner published a famous study in 1949, The fate of the foreskin, described as "a model of perceptive and pungent writing." It revealed that for the years 1942–1947, about 16 children per year in England and Wales had died because of circumcision, a rate of about 1 per 6000 circumcisions. The article had an influential impact