Migration and the Life Cycle

Our discussion of various types of internal migration illustrates the fact that both push factors and pull factors change over the course of the life cycle. Those factors important to the migration decision of young people, for example, tend to be quite different from those important to the elderly.

Important changes in an individual's life-style as he or she progresses through the life cycle often result in migration. Marriage, childbirth, divorce, job or career changes, retirement, disability, and death of a spouse are prime examples. Since many major life changes are concentrated in young adulthood, those in their late teens, twenties, and thirties are far more likely to move than those in their forties and fifties (Figure 3-18). A secondary increase in the tendency to migrate occurs in late middle age. Migration is often stimulated by retirement and the movement of grown children away from home.

Figure 3-18. Migration Tendencies and Age. The probability that a person will move varies with age. People in their twenties and thirties are much more likely to move than those in their forties and fifties. A secondary peak occurs following retirement and other major events associated with the aging process

In the developed countries, migration of retired persons has increased considerably since World War II. Of course, pull factors important to retirees differ from those of younger working adults. Typically, the elderly worry about the cost of living on a fixed income, the cost and availability of health care, and the availability of recreational opportunities.

In the United States, the Sunbelt has long been a prime destination for retirees. Initially, large numbers of retirees settled in southern California and southern Florida. High living costs and high crime rates have made these areas less attractive to elderly retirees. More recently, parts of northern Florida, western North Carolina, northern Arkansas, Texas, and Arizona have become favored destinations for retired people.

Within the elderly population, of course, it is the younger and more vigorous who make the decision to retire to the Sunbelt or to a familiar recreation area. As the infirmities of old age set in, elderly people lose the opportunity to make locational decisions for themselves.

Some very elderly persons can no longer care for them-selves, and their children or other relatives must make the necessary arrangements for them. Once the decision to place elderly people in care facilities has been' made, the choice among alternative facilities suits the needs of relatives and physicians, not the needs of the elderly them-selves. Migration decisions are no more voluntary for the very elderly than they are for very young children.

Summary. The importance of population processes and their effects on human geography was demonstrated in this chapter. The population of the world is highly clustered, with major concentrations found in East Asia, South Asia. Southeast Asia, Europe, and North America. These areas report the highest population densities in the world. The concept of population density fails to account for the quality of a region's land base, however. Physiological density and agricultural density more accurately measure a population's ability to support itself.

In order to examine population changes over time, geographers study birth rates, death rates, and migration. The crude birth rate is the ratio of births to the total population. Birth rates are closely related to levels of economic development. Crude death rates are calculated in the same way as crude birth rates. The difference between a country's crude birth rate and its crude death rate is its rate of natural increase or decrease.

The demographic transition model helps to explain the association between population growth and economic development. For example, the model explains why the world's highest rates of population growth are concentrated in less developed countries. The concentration of high birth rates in these countries has induced many to question the desirability of rapid population growth. Malthusians regard population growth as undesirable because more people put more strain on a limited resource base. Others point out that human beings are highly capable of creating new resources, thus disputing the Malthusian view. Those who support the Malthusian view have argued that governments should adopt policy measures intended to lower birth rates.

International and internal migration have had important effects on populations throughout the world. The many reasons that people move are grouped into push factors, which encourage people to move, and pull factors, which encourage them to select specific destinations. Some people are involuntary migrants. Forced migration has occurred throughout recorded history. Today, many migrants are refugees who relocate in response to political disruption, violence, and persecution in their home countries.

Many natives of less developed countries have moved to the United States, Western Europe, and other wealthy regions. Immigrants comprise a substantial proportion of the labor force in many developed countries. Guest workers are temporary migrants who move to developed countries to improve their economic circumstances. Other international migrants are highly educated professionals. The age-specific nature of migration out of the Third World affects the age structure of origin communities, but origin communities often benefit from the transfer of wages home by migrating workers.

Migrants within countries also respond to push and pull factors. Migrants often evaluate search spaces on the basis of place utility. The gravity model predicts that migration between two places can be predicted on the basis of population and distance. Many large migration flows are explained on the basis of long-standing place ties between origin and destination, which results in channelized migration.