Research

The Malawi Longitudinal Study of Families and Health (MLSFH) provides a rare record of 25 years of longitudinal population data in one of the poorest countries in the world, and it is one of very few long-standing publicly-available longitudinal cohort studies in a sub-Saharan African (SSA) context. I have been part of the MLSFH since its inception, have directed it since 2006, and have shaped its evolution from a narrowly-focused reproductive health study to a major social science project studying topics ranging from child & adolescent development to aging, ADRD and epigenetic determinants of health. MLSFH research is currently funded by three NIH R01 grants focusing on different aspects of the lifecourse: Adversity, Aging and ADRD Risk among the Global Poor: A Biosocial Approach (NIA R01 AG079527), Surviving an Epidemic: Families and Well-being (NICHD R01 HD087391) and Adversities, Health and Resilience in Early Adulthood: An Intergenerational, Low-income Country Study (NICHD R01 HD114246). MLSFH data are made publicly available, providing a major resource for studying health across the lifecourse, and more recently aging and ADRD, in an African low-income population. Learn more about the MLSFH at https://www.MLSFHresearch.org. 

Selected Publications:

• Purcell, H., I.V. Kohler, A. Ciancio, J. Mwera, A. Delavande, V. Mwapasa and H.-P. Kohler (2024). Mortality Risk Information and Health-Seeking Behavior during an Epidemic. Proceedings of the National Academy of Sciences 121(28): e2315677121. 

• Ciancio, A., A. Delavande, H.-P. Kohler and I.V. Kohler (2024). Mortality Risk Information, Survival Expectations and Sexual Behaviours. Economic Journal 134(660): 1431-1464.

• Ciancio, A., J.R. Behrman, F. Kämpfen, I.V. Kohler, J. Maurer, V. Mwapasa and H.-P. Kohler (2024). Barker's Hypothesis among the Global Poor: Positive Long-Term Cardiovascular Effects of in Utero Famine Exposure. Demography 60(6): 1747-1766.

• Kohler, H.-P., S.C. Watkins, J.R. Behrman, P. Anglewicz, I.V. Kohler, R.L. Thornton, J. Mkandawire, H. Honde, A. Hawara, B. Chilima, C. Bandawe, V. Mwapasa, P. Fleming, and L. Kalilani-Phiri. 2015. Cohort Profile: The Malawi Longitudinal Study of Families and Health (MLSFH). International Journal of Epidemiology 44(2): 394-404.

• Kidman, R., J. Mwera, Y.T. Rui, E. Breton, A. Zulu, J. Behrman and H.-P. Kohler (2024). Cohort Profile: The Adverse Childhood Experiences Cohort of the Malawi Longitudinal Study of Families and Health. BMJ Open 14(5): e079631.

Global aging and the associated rise of dementia is one of the foremost public-health and health policy challenges for the next decades. Yet, Aging in rich and poor populations differs not simply in terms of life expectancies and health at various ages. Instead, the biosocial aging process is likely to start diverging in early life, with differences accumulating into old age as a result of the interactions of behaviors, social contexts and the biological embedding of lifecourse adversities.  Distinct social contexts, including some that might increase resilience (e.g., social integration of the old), imply that determinants of healthy aging in low-income countries is likely to differ from the patterns established so far.  Intersecting with my research interests in global health, comparative analyses and statistical inference, I have increasingly been engaged in studies of aging and ADRD across diverse contexts, ranging from very low- to very high-income contexts, with an emphasis on how the determinants of aging and ADRD in diverse populations are shaped by local contexts, lifecourse transitions, early-life adversity, social policies and other aspects. 

Selected Publications:

• Hoang, C.T., I.V. Kohler, V. Amin, J.R. Behrman and H.-P. Kohler (2023). Resilience, Accelerated Aging, and Persistently Poor Health: Diverse Trajectories of Health in Malawi. Population and Development Review 49(4): 771-800.

• Kohler, I.V., F. Kämpfen, C. Bandawe and H.-P. Kohler (2023). Cognition and Cognitive Changes in a Low-Income Sub-Saharan African Aging Population. Journal of Alzheimer’s Disease 95(1): 195-212.

• Ciancio, A., J.R. Behrman, F. Kämpfen, I.V. Kohler, J. Maurer, V. Mwapasa and H.-P. Kohler (2024). Barker's Hypothesis among the Global Poor: Positive Long-Term Cardiovascular Effects of in Utero Famine Exposure. Demography 60(6): 1747-1766.

• Amin, V., J. Behrman, J. Fletcher, C. Flores, A. Flores-Lagunes and H.-P. Kohler (Conditionally Accepted). Does Schooling Improve Cognitive Abilities at Older Ages: Causal Evidence from Nonparametric Bounds. Demography.

I have a long-standing research agenda focused on the causes and consequences of very low fertility, a phenomenon often perceived – albeit possibly incorrectly so – to threaten the sustainability of many European social security systems and the foundation of economic growth in European societies. The summary paper of this research agenda on "The Emergence of Lowest-Low Fertility in Europe" used new demographic methods to establish the concept of lowest-low fertility, and it provided an integrative path-dependent socioeconomic theory of explaining the rise of lowest-low fertility in Southern, Central and Eastern Europe during the 1990s. This paper is among the most widely cited paper published in Population and Development Review. Following up on this research, we published a paper in 2005 on the contributions of having children to individual happiness, which stimulated a renewed scholarly interest in the connection between having children and individual well-being that has received substantial press and media coverage. In 2009, we published a further seminal paper in Nature, “Advances in Development Reverse Fertility Declines,” that challenged the conventional wisdom that advances in development among the most advanced countries continues to depress fertility. We argued to the contrary, showing that increasing development in advanced countries is associated with higher fertility and may actually contribute to elevating fertility levels. This controversial finding has stimulated a large body of theoretical and empirical follow-up research, advancing at the moment both the sociological, demographic and economic understanding of the interaction between fertility and development in advanced societies. One possibility to achieve this improved understanding is outlined in a book on Understanding Family Change and Variation: Toward a Theory of Conjunctural Action (with J. Johnson-Hank, C. Bachrach, S.P. Morgan) that postulates a new theoretical framework that integrates family demography with social theory and that synthesizes knowledge from social and cognitive sciences. 

Selected Publications:

• Myrskylä, M., H.-P. Kohler, and F.C. Billari (2009). Advances in Development Reverse Fertility Declines. Nature 460(7256): 741-743.

• Kohler, H.-P., J.R. Behrman, and A. Skytthe (2005). Partner + Children = Happiness? The Effects of Partnerships and Fertility on Well-Being. Population and Development Review 31(3): 407-445.

• Kohler, H.-P., F.C. Billari, and J.A. Ortega-Osona (2002). The Emergence of Lowest-Low Fertility in Europe During the 1990's. Population and Development Review 28(4): 641-680.

• Kohler, H.-P. and D. Philipov (2001). Variance Effects in the Bongaarts-Feeney Formula. Demography 38(1): 1-16.

The analysis of networks has become a prominent theme in contemporary demographic research in both developed and developing countries, including investigations of the determinants of fertility behaviors, the interaction between social network and social structures and population policies, the role of intergenerational networks in aging societies, and the relevance for sexual networks for the spread of HIV AIDS. My research has made important contributions to the understanding of social networks, and the interrelations between social networks and health/demographic behavior. My dissertation Fertility and Social Interactions: An Economic Perspective (Oxford U Press, 2002) pioneered the integration of social networks and information diffusion in economic models of fertility behavior, and subsequent research with the Malawi Longitudinal Study of Families and Health (MLSFH) documented how social networks affect fertility behavior, HIV risk perceptions and HIV prevention strategies in rapidly-changing social context. In collaboration with S. Helleringer, we also have created the Likoma Network Study (LNS), an innovative study that investigated the interaction between HIV risks, sexual behaviors, population-level sexual networks, epidemiological dynamics and HIV prevention policies within a sociocentric network framework.

Selected Publications:

• Kohler, H.-P., S. Helleringer, J.R. Behrman, and S.C. Watkins. 2015. The Social and the Sexual: Networks in Contemporary Demographic Research. Pp. 196-237 in Population in the Human Sciences: Concepts, Models and Evidence, P. Kreager, B. Winney, S. Ulijaszek, and C. Capelli. Oxford: Oxford University Press.

• Helleringer, S. and H.-P. Kohler. 2007. Sexual Network Structure and the Spread of HIV in Africa: Evidence from Likoma Island, Malawi. AIDS 21(17):2323-2332.

• Kohler, H.-P., J.R. Behrman, and S.C. Watkins. 2001. The Density of Social Networks and Fertility Decisions: Evidence from South Nyanza District, Kenya. Demography 38(1):43-58.

• Kohler, H.-P. (2001). Fertility and Social Interactions: An Economic Perspective. Oxford: Oxford University Press.

I have become increasingly involved in the evaluation of social, population and health policies that are often seen as essential components of achieving sustainable development and healthy aging. A key challenge in such evaluations is the creation of evaluation criteria that are comparable across heterogeneous domains, are based on solid empirical evidence (and ideally causal studies), and reflect dynamic life-course and socioeconomic interactions. I worked with the Copenhagen Consensus Project, a global think tank collaborating with a panel of leading economists, including several Nobel Laureates. In 2011, I participated in an evaluation of policies to reduce the sexual transmission of HIV (with J.R. Behrman). I returned in 2012 with an evaluation of global policies that addressed concerns about population growth. Then in 2014, I participated in an evaluation of essential population-related post-2015 Millennium Development Goals (focusing in particular on low fertility and population aging, population growth, human capital and population change, and urbanization). In more recent work, we have also used causal-inference and related methods methods to identify the behavioral and health effects of population-based NCD-health screenings, the provision of health or mortality information, and local community structures. 

Selected Publications:

• Ciancio, A., F. Kämpfen, H.-P. Kohler and R. Thornton (2024). Surviving Bad News: Health Information without Treatment Options. American Economic Review: Insights 19(1): 2335356.

• Ciancio, A., F. Kämpfen, H.-P. Kohler, and I.V. Kohler (2021). Health Screening for Emerging Non-Communicable Disease Burdens among the Global Poor: Evidence from Sub-Saharan Africa. Journal of Health Economics 75:102388.

• Kohler, I.V., F. Kämpfen, A. Ciancio, J. Mwera, V. Mwapasa, and H.-P. Kohler (2022). Curtailing Covid-19 on a Dollar-a-Day in Malawi: Role of Community Leadership for Shaping Public Health and Economic Responses to the Pandemic. World Development 151:105753.

• Kohler, H.-P. (2013). Population Growth. Pp. 510-580 in Global Problems, Smart Solutions: Costs and Benefits, B. Lomborg. Cambridge, MA: Cambridge University Press.