Research

Research projects in formal demography — the demographic transition in Brazil, population aging and its demographic components, age reporting in Brazil’s COVID-19 vaccination records, and net migration in Brazil, 1960–1980 — each with a reproducible companion site.
re·search AmE /rɪˈsɝːtʃ/ · BrE /rɪˈsɜːtʃ/ noun Systematic inquiry into population change — fertility, mortality, and migration — to explain how age structure and social institutions evolve across time and place.

Demographic transition in Brazil

Youth and old-age dependency ratios for Brazil and its five regions, 1872-2070

Census counts from 1872 to 1991, IBGE's coverage-adjusted estimate for 2000, and IBGE projections to 2070, showing Brazil's transition from high mortality and fertility to an aged population structure.

The companion site provides growth rates and dependency ratios for Brazil and federative units through 2070 (Turra and Fernandes 2026), and demographic dividend estimates it computes from them.

World population aging as a function of period demographic conditions

Rejuvenating effect of deaths by rejuvenating effect of births, 236 countries, 1950–2100

Period decomposition of population aging across 236 countries and areas, 1950–2100, using the Preston–Himes–Eggers decomposition.

The paper (Fernandes et al. 2023) used the 2022 revision of UN World Population Prospects; the companion site recomputes its decomposition with WPP 2024 and provides interactive country-year estimates of rejuvenating effects and aging stages.

COVID-19 vaccination & age reporting, Brazil

Age-quality indicators comparing Brazil vaccination records and Sweden

A demographic audit of age reporting in Brazil's national COVID-19 vaccination database, benchmarked against census data, projections, and Sweden.

The companion site provides R code and reference data for a study comparing oldest-old population estimates from administrative vaccination records and census data in Brazil (Turra et al. 2023).

Migration estimates, Brazil 1960–1980

Net migration rates in Brazil by residence area, 1960-1970 and 1970-1980

Net migration estimates by sex, age group, and urban/rural residence for Brazilian states during 1960-1970 and 1970-1980.

Between 1960 and 1980, rural areas recorded a net migration loss of 26.1 million and urban areas a net gain of 24.0 million. The project documents those shifts with more than 6,500 public estimates from Fernandes and Carvalho (2024).