218. In actual fact, hlstorlcal mrtality declines have not been neutral. Mortality has generally declined in absolute terms more atlDng the young and old inA/ 40 /5L9 Engli sh Page I02 the Population than among the prime age popuracion, wbi.ch comprises tbe majority ofthe rabour force- This pattern of mortality declina has the expected effect on agest.ructure and relative 1abour supply: the proportion of the population at theyoung and old ages increases relative to those in the traditionar rabour forceages. To quantify this result, a simple comparison can be made of Cr{opopulations, Both experience the same level of fertility (a total fertility raCeof 5'0) but vary according to rheir rever. of mortality. The first popurationexhibits a life expectancy at birth of 40 years, typical of a country before theonset qf the norCality transition. The second population exhibits a lifeexpectancy of 65 years at birth, typicat of a country nearing the end of itsmortality transition. The described mortarity transition may be expected to takeplace over a quarcer-century or longer. Both populations are assumed to experrenceage-specific labour force participation rates typical of a country at a ,,middIe,, Level of modernization, !!/ and, for cbe sake of example, only the male popura tionhas been fipdeled. Results for females would differ only because of the .lifferentlevel of labour force participati.on exhibiteal.
**Analysis**
The text discusses the impact of mortality decline on population structure and labor supply, which is a topic typically associated with economic development and demography. The text also mentions life expectancy, labor force participation rates, and fertility rates, which are all indicators of economic development and demographic changes.

**Category**
Economic development, Health