RESUMO
PIP: This article discusses Frejka's analysis of alternative paths to zero population growth. A net reproduction rate (NRR) of 1 is a vital step in reaching zero growth, but because of age distribution variances, it does not necessarily represent zero growth. The projections described here include: 1)the immediate path of achieving NRR of 1 in 1970-1975: 2)rapid path of an NRR of 1 in 2000-2005: and 3)slow path of NRR of 1 in 2040-2045. The population of the world in the year 2000 would be respectively: 5,700,000,000; 6,000000,000; and 7,000,000,000. Zero growth would be reached in 2000 for the immediate path; in 2100 with a population of 8,000,000,000 in the rapid path; and in 2045 with a population of 15,000,000,000. Individual projections are also given for several countries on different continents.^ieng