Purpose
The Kagera Health and Development Survey (KHDS) is a longitudinal study that examines the long-term wealth dynamics of households and individuals in north-west Tanzania. It is one of the longest-running African studies of its kind. The study involves a panel of households who were originally surveyed for four rounds between 1991 and 1994, then re-surveyed by EDI Global in 2004 and 2010, where we administered a multi-topic household questionnaire to all split-off households, including those that had moved out of the baseline location. This panel dataset offers valuable insights into long-term poverty persistence and economic growth in rural households, as well as intergenerational trends as the children of the original respondents have now formed their own households. Interviewing people who moved out of their baseline location is especially important for understanding how migration and economic development are interconnected.
KHDS 2010 was primarily funded by the Rockwool Foundation and the World Bank, with additional funds provided by the Hewlett Foundation through the Agence Inter-établissements de Recherche pour le Développement (AIRD). The 2004 round was funded by the Knowledge for Change Partnership Trust Fund at the World Bank and DANIDA. KHDS offers a unique opportunity to explore the mechanisms of poverty persistence and economic growth over nearly 20 years in rural Tanzania, providing valuable insights into the impact of policy interventions on households and communities.
Action
EDI Global conducted longitudinal data collection for KHDS, revisiting 4,336 individuals who were interviewed nearly 10 and 20 years ago. KHDS is one of the few household surveys that has data over such a long period and that can address questions regarding the long-term effects of childhood circumstances. This provides a unique opportunity to evaluate who stayed in poverty over this period and who moved out of poverty, and how. The sampling strategy for KHDS 2004 and KHDS 2010 was to re-interview all individuals who were household members in any wave of the KHDS 91–94, totalling 6,355 people. EDI Global collected information about all household members that were alive during the last interview in 1991–1994 but were found to be deceased by the time of the fieldwork in 2004 and 2010, in a mortality questionnaire.
Excluding households in which all previous members were deceased, EDI Global managed to track and re-contact 93% (746) of the baseline households for KHDS 2004. Of these 746, 96% of households were re-interviewed, and 82% of all respondents were re-interviewed, excluding people who had passed away. The re-contact rates for KHDS 2010 were similar to those achieved in KHDS 2004. As in 2004, older respondents, if alive, were much more likely to be re-contacted than younger respondents. In the oldest age category EDI Global teams managed to re-contact almost 98% of all survivors. More than 50% of the re-interviewed panel respondents were located in the same community as in KHDS 91–94. Overall, EDI Global achieved a highly successful tracking rate.
In 2010, 88% of the original 6,353 respondents had either been located and interviewed or, if they were deceased, sufficient information regarding the circumstances of their death were collected. Nearly 14% of the re-contacted respondents were found in regions other than Kagera, and EDI Global teams also tracked panel respondents in Uganda, where 1% of the interviewed panel respondents were located.
Impact
EDI Global successfully tracked respectively 85% and 88% of the 6,353 original respondents for both KHDS 2004 and KHDS 2010, and interviewed 4,430 and 4,336 individuals, respectively. Additionally, information on mortality was collected for deceased respondents.
For KHDS 2010, we administered electronic survey questionnaires on handheld computers, and conducted a formal comparison of electronic versus paper-based data collection methods through a randomised survey experiment. The results of this experiment were published in the peer-reviewed article Beegle, K., De Weerdt, J., Friedman, J. and Gibson, J. 2012. Methods of household consumption measurement through surveys: Experimental results from Tanzania. Journal of Development Economics, 98(1), pp. 3–18.
Since the first KHDS paper was published a quarter of a century ago, well over 100 journal articles have been written using these data. These papers cover a broad range of topics, including HIV/AIDS, orphanhood, adult mortality, migration, urbanisation, inheritance, marriage, family networks, intergenerational persistence of poverty, and the long-term impact of HIV/AIDS. See a list of papers here: https://www.uantwerpen.be/en/staff/joachim-deweerdt/public-data-sets/khds/#papers
In addition to the main KHDS data, several auxiliary datasets have been used to complement the KHDS data and are available here. These include NASA weather data, data on the distance to borders, price data, consumption data and assets aggregates, and data on weddings and bride prices.
