This is the first of five chapters which focus on submodels within TARGETS. The framework of the Population and Health submodel includes socio-economic and environmental pressures, simulations of fertility, disease-specific mortality and morbidity, and their impact on population size, structure and health levels. The response subsystem comprises policies in the field of fertility and health. Whereas there are a number of separate models of fertility and population, the innovative aspect of the approach adopted here is that it is highly integrative, incorporating both population and health dynamics.

Introduction

During the past century, most populations of the world have experienced an increase in their levels of social welfare and economic development. These changes have shown a concomitant increase in the average life expectancy at birth and a decrease, although slower, in fertility levels (UNFPA, 1996; World Bank, 1993). The result has been an increase in world population size and a demand for resources unprecedented in history (UN, 1992; WCED, 1987). Reduction of health risks and the increased access to health services have resulted in a world-wide average life expectancy of more than 65 years during the past decades (WHO, 1996). Even though fertility rates are dropping, for some countries even rapidly, the world population is still growing at 1.5% per year. Presently, world population size in the year 2050 is estimated to be determined for about 50% merely by the present size of the fertile female population.