Even if we could determine the right size of population for given country, such a balance would not be easy to achieve. The rate of population growth is fastest in technologically underdeveloped countries. In many of these countries a high birth rate is accompanied by a death rate which has been lowered by modern drugs and improved! Standards of public health. (46) Ideally it should be possible to counterbalance the effect of a reduced death rate by an increased use of family planning. In practice, however, population control is a highly complex matter which involves more than the availability of contraceptive device. Throughout history people have determined the size of their families, whether large or small, according to the cultural values of the society in which they live.

Population control, then, is socially as well as biologically determined. For example, it is known that voluntary family planning programs do not become effective until after the population has begun to fall, this finding is not as paradoxical as it seems. As living standards rise, a large family is no longer necessary as an insurance against the future. Consequently, birth rates may begin to fall independently of any official family planning campaign, be some eases, a downward shift in population seems to come about automatically as a society develops industrially. (47) If eventually the whole world pauses through the transition from an agricultural to a modern industrial economy, can we assume that birthrates will fall to manageable levels without the imposition of enforced family planning? Again there is a problem， since many economists doubt whether there ai*e enough resources in the world for the necessary level of industrial development to be achieved universally.

The advantages and disadvantages of a large population have long been a subject of discussion among economists. On the one hand it has been argued that the supply of good agricultural land is limited. In order to feed a large population, inferior land must be cultivated and the good land worked very intensively. As a result, each person produces less in a given amount of time and this means a lower average income than could be obtained with a smaller population. (48) Other economists have argued that a large population gives more scope for specialization and the development of facilities such as ports, roads and railways, which are not likely to be built unless there is a big demand to justify them. Similarly, it can be argued that many of the overhead costs of society, such as those involved in providing the basic framework of government, are less burdensome to each individual if they are shared among the members of a large population.

(49) One of the difficulties in implementing a world-wide birth control programme lies in the fact that official attitudes to population growth vary from country to country depending on the level of industrial development and the availability of food and raw materials. In one of the underdevdoped countries Were a vastly expanded population is pressing hard upon the limits of food, space and natural resources, it will be the first concern of government to place a limit on the birthrate, whatever the coasequences may be. In a highly industrialized society the problem may be more complex. A declining birthrate may lead to unemployment because it results in a duninishing market for manufactured goods. Cities with a declining population may have to face the prospect of a shrinking lax base and perhaps a fall in land values. If there are fewer children going to school, teachers may be thrown out of work (50) When the pressure of population on housing declines, prices also decline and the building industry, with its many ramifications throughout the economy, is weakened. Faced with considerations such as these, the government of a developed country may well prefer to see a slowly increasing population, rather than one which is stable or in decline.