The population of Zambia: past, present and future

Abstract Background The population size, age structure, and the changes thereof have significant effects on a country’s social, economic and political dispensation. Understanding future fertility and mortality trends is key in forecasting future population patterns and levels; an outcome crucial for planning for the changing population age structure, economic and social needs as well as the geopolitical space. In this paper, we used fertility, mortality and migration forecasts from expert opinions to project the population of Zambia from the year 2015 to 2060 and consequently discuss what this may mean in terms of implications both for population programming and policy changes. Methods In order to project Zambia’s future population size, PADIS INT, a deterministic modelling tool capable of supporting multi-scenario and multi-group forecasts with extensive horizons was used. Projections were split into three variant-based scenarios, which included – a reference scenario also called medium, alternative scenarios (plunge and enhanced) – based on the rate of change of fertility, mortality and migration. Results The medium scenario projects the population growth rate at 2% per annum in 2060, a drop of about 0.8% percentage points from the 2015 growth rate. The medium variant shows further that the population will reach a high of 49.4 million people in 2060 representing a 2.1 times increase in population size from the base of 16.1 million people in 2015. Our findings also indicate a shifting age structure in the medium scenario from 3% to 6% of the population age 65 years and above. Overall dependency ratio will reduce from 92% to 61% while old age dependency will increase from 5.8% to 9.7% between 2015 and 2060. TFR would reduce from 4.8 in 2020 to 3.2 in 2060 and RNI from 29% to 20% during the same time interval. The medium scenario projects that a bit more people are likely to leave Zambia with a net migration of 62 persons per 100,000 population in 2020 and 43 persons per 100,000 population in 2060. Conclusions These results show that while the population will increase significantly for the period in question, fertility will continue to reduce; these results are consistent in both the reference and alternative scenarios. These results may be indicative of improvements in female education attainment, female participation in remunerable work, as well as better sexual and reproductive health and rights. Continued population growth has other several policy implications for the social, economic and political development of Zambia. Such population projections as conducted in this paper ideally supplement conventional data collection processes necessary for national development planning and policy space adjustment.