"In 1962, Population Council gave Guttmacher a grant “to travel around the world to assess what methods of birth control they should back.” He reported that conventional contraceptives were not working and advised the council to invest in development of the IUD. The council invited forty-two clinicians to a conference on intrauterine contraception. Tietze remembered the “conspirational air” that surrounded the conference “It was a very exiting period. . . . we were working with something that had been absolutely rejected by the profession . . . we had a great feeling of urgency to produce a method that worked. It seemed to work. Now we had to establish it. And we had to start from scratch.” The council invested more than $2.5 million in the clinical testing, improvement, and statistical evaluation of the IUD, which proved to be highly effective for the approximately seven out of ten women who could retain one. Tietze, an unusually candid man with the habit of precise expression, recalls the care with which clinicians were recruited and the effort poured into making sure that their records were accurate. There was such a feeling of urgency among professional people, not among the masses, but something had to be done. And this was something that you could do to the people rather than something people could do for themselves. So it made it very attractive to the doers. Armed at last with a method that was inexpensive and required little motivation from the user beyond initial acceptance, family planning programs began to have an effect on birth rates in South Korea, Taiwan, and Pakistan. By 1967 a review article in Demography criticized the over optimism of the Population Council technocrats about the prospects for controlling world population growth. Other social scientists claimed that population control was getting too much of the development dollar and pointed out that population control was no substitute for social justice. Lower birth rates did not guarantee a better society. Whether or not world population growth could be controlled remained an unanswered question."