It was in 1974 that the first International Conference on Population attended by representatives from many governments was held in Bucharest, Romania. This conference was an important landmark to address the issue of population explosion that was critically threatening the survival of human beings. A revolutionary stride was made at this conference to defeat opposition to fertility control on the grounds of ideological and religious beliefs.

In the three decades since the Bucharest conference, population growth control centering on family planning has been more successful than anticipated. The world population increased from 2.5 billion in 1950 to 6 billion in 2000, but the annual growth rate was successfully lowered from 2 percent to 1.2 percent in those 50 years.

With the success of population control, the last International Conference on Population and Development (ICPD) in Cairo in 1994 focused on the issue of reproductive health of women, covering their birth, growth and health throughout their life. The member states agreed to make the improvement of women's reproductive health the greatest goal for their national population policies. Reproductive health services had been developed in industrialized countries even before World War II, but reproductive health service systems cannot be easily developed in the majority of developing countries. Financial assistance is required to meet individual needs of developing countries to improve their reproductive health services that occupy a great portion of the ICPD Program of Action.

The strong impression that I had through reviewing the report of the ICPD for the past year is that it does not give a more detailed explanation to each agenda item. In other words, analyses based only on practical research on population are given. The introduction of mathematics into research statistics after the war facilitated the development of mathematical economics, mathematical sociology and social engineering. Demography has also been influenced by the remarkable development of demographic statistics, and study on theorization efforts has been slighted.

There are urgent needs both for new theoretical and empirical research development for population transition or for leading "population" factors to play positive roles, as I believe that basic theoretical analysis of world demographic changes is an urgent task for this century.