Project Summary/Abstract The extraordinarily rapid aging of the developing world represents one of the most significant demographic transformations in history, with profound consequences for disease and disability, intergenerational relations, work and retirement, geographic mobility, and other economic and demographic processes. The United Nations projects that the population aged 60 and older will grow by over 50% over the next 15 years. Most of the growth of the older population will take place in the Global South, which will include 80% of the older population by 2050. The growth of the older population in Latin America, Africa, and South Asia is occurring far more rapidly than it did in the developed countries of Europe and North America. Despite its manifest significance, population aging in the Global South is understudied, partly because of a dearth of suitable data. To grapple with processes of population aging across the Global South over multiple decades, researchers must have access to big microdata. Over the past two decades, the Integrated Public Use Microdata Series (IPUMS) has created a vast database of census and survey microdata covering most of the globe from the 1960s to the present. These data include detailed information about each person's geographic location, demographic characteristics, and economic activities. The data also cover education and literacy, fertility history, migration and place of former residence, marital status and consensual unions, disabilities, water supply, sewage, housing features (e.g., floor and roof material), and a host of other characteristics. This competing continuation proposal requests funding to expand and adapt the world’s most comprehensive collection of census microdata to meet the needs of research on aging in the Global South. We have four specific aims: (1) Data acquisition and long-run preservation. We will obtain and preserve census and survey microdata from the Global South, including the newest microdata from household surveys and older data at risk of destruction. (2) Data processing. We plan to expand the IPUMS database by adding data for approximately 100 million individuals included in 40 censuses and surveys, focusing on recent data from Africa and Latin America. This expansion will require data cleaning, development of comprehensive machine-processable metadata, spatial data ingest and harmonization, and variable harmonization. (3) Innovations in data, metadata, and technical infrastructure. We will make major improvements to IPUMS data and metadata while adding new capabilities to IPUMS data processing and dissemination systems. (4) Dissemination and outreach. We will provide user support, training, and outreach and will develop new online training capabilities. We will harness the expertise of the user community and promote collaboration and scientific discovery through surveys of users, workshops, and online interaction. Most critically, we will maintain our network of co...