Although those concerned with the developmental problems of the non-industrialized world have paid lip service to the population explosion in the last decade, it is only very recently that they have taken practical steps to influence the situation. It is widely recognized that in many parts of the world there is a "population problem": the high rate of increase in population makes social and economic development difficult if not impossible. Large-scale efforts to control fertility are, to be sure, not unknown. A number of governments have assumed the responsibility of providing their people with information and services on family planning, and some countries have organized major national programs. Since any change in birthrate depends on individual decisions by large numbers of husbands and wives, it is essential to know first of all how the people concerned feel about family size and limitation.