First, AIDS has a demographic impact and alters the age composition of the population and the labour force. These changes in the numbers of workers of different ages are captured in the L.t term. A change in the age composition of the labour force alters the productivity of the labour force because of its impact on accumulated work experience, and this is captured in the p. term. With population growth averaging 1.9 per cent a year, however, GDP per capita grows more slowly than GDP, at 2.6 per cent a year.