Projeções populacionais para áreas subnacionais de Moçambique por idade e sexo até 2047

Abstract

The objective of this study was to project the population of subnational areas of Mozambique (provinces and districts) by age and sex for the period from 2022 to 2047, using the CohortComponent Method based on data from the National Institute of Statistics (INE) and the United Nations. To achieve this, census data from 2007 and 2017, provided by the National Institute of Statistics (INE), were used as the basis for developing the population projections. The method adopted was the cohort-component approach, which relies on the age distribution derived from survival ratios, allowing for more accurate capture of demographic dynamics through their fundamental components. In the course of the research, two projection exercises by age and sex were carried out for Mozambique's provinces. In the first methodological exercise, we used the population projections made available by INE for the period from 2017 to 2047. These projections were available on the INE website for each province, which were considered as large areas in this study. From this data, we projected the population of the districts treated here as small areas based on age distribution and the cohort behavior over time. Thus, the provinces served as a reference to disaggregate the data and estimate the demographic evolution of the districts with the level of detail required by the study. A second methodological exercise, complementary and alternative to the first, was also developed. In this exercise, we used the United Nations projections for Mozambique as a whole, treated as a broad area, to build our own projection model. From the UN data, we first projected the population of the provinces, now treated as smaller areas. For this, we again applied the Cohort-Component Method, ensuring internal consistency between age groups and sexes over time. This exercise made it possible to construct an alternative projection for the provinces, based on international parameters and with clearer and more accessible methodology. In the final stage of the second exercise, with our own provincial projections in hand (developed from UN data), we carried out a new projection for the districts, now using these provinces as major areas. Therefore, the districts were projected a second time, but now based on the provinces derived from our own projection model, ensuring greater methodological consistency and comparability between the two exercises. This strategy of dual district projections one based on INE data and another based on the custom projections allowed us to contrast the results obtained under two distinct scenarios, enhancing the analytical robustness of the study and contributing to a more critical interpretation adapted to Mozambique's demographic specificities. Throughout the study, when referring to this custom population, the term "own projection" is used. The projections carried out by INE for the provinces were made using the demographic components method. The projection results for all districts of Mozambique, for the period from 2022 to 2047, show variations in average annual growth rates, with population losses in some districts and excessive growth in others. The differences between INE’s projections and the own projections vary considerably by age group and province, revealing distinct patterns in the modeling of demographic indicators. It is observed that, for most provinces, the difference between the projections tends to be negative over time for both males and females. This indicates that the own projections point to a larger total population compared to the INE projections. This behavior suggests methodological differences between the approaches used, which may be related to different assumptions regarding fertility, mortality, and migration. However, one notable aspect of the analysis is that in older age groups, the difference between the projections becomes positive, indicating that INE's projection anticipates a larger population in comparison to the own projection. A similar scenario is observed at the district level, where, when analyzing the differences by sex, it is seen that in several districts, the projections for the male population are consistently higher than those for the female population. This phenomenon suggests that the male population dynamics may be projected more robustly, possibly due to differential rates of migration, mortality, or other specific demographic factors. However, there are districts where the opposite occurs: the projections for the female population are substantially higher than those for males, indicating a possible concentration of women in certain regions. This disparity may be related to sex-selective migration patterns, mortality differences, or even socioeconomic factors that influence the permanence of men and women in specific locations. The own projections indicate that the population of Mozambique will reach approximately 60,117,595 inhabitants by 2047, with an average annual geometric growth rate of 2.47%. Among the provinces, Maputo, Nampula, and Zambézia will experience the highest population growth, while Sofala and Tete will see more moderate increases. At the district level, the districts with the highest population growth by 2047 are Matola, Tete, and Nampula, with annual growth rates of 1.28%, 1.25%, and 1.16%, respectively. In contrast, the districts with the lowest growth include Massangena, Chimonila, and Chigubo, with growth rates of 0.93%, 0.74%, and 0.83%, which may be related to factors such as migration and varying demographic transitions across regions. These results are important for demographic planning and for the development of public policies aimed at spatial population distribution in the country.