Marc Klemp

This research theme explores how population characteristics shaped by ancient human migration patterns influence contemporary economic, political, and social outcomes. My work establishes a fundamental link between the genetic diversity resulting from human migration out of Africa tens of thousands of years ago and modern phenomena such as civil conflict, institutional development, and economic performance.

Using novel datasets on population diversity and advanced econometric methods, I've shown that diversity has both beneficial and detrimental effects on societies. While intermediate levels of diversity foster innovation and creativity through the interplay of varied cognitive approaches, excessive diversity can lead to reduced social cohesion, interpersonal trust, and increased civil conflict. These insights help explain persistent differences in the wealth of nations and provide a deeper understanding of societal development.

My research in this area contributes to our understanding of how deeply-rooted factors continue to influence modern economic and political outcomes, with important implications for policy approaches to managing diversity in contemporary societies.

This research theme investigates the relationship between demographic behaviors and economic outcomes, with particular focus on the quantity-quality tradeoff in children. My work uses unique historical datasets, including reconstructed genealogies spanning centuries, to demonstrate how reproductive decisions influenced human capital formation and contributed to modern economic growth.

A key finding from this research is that moderate fecundity maximized long-run reproductive success. Using data from Quebec covering 1608-1800, I've shown that while higher fecundity led to more children in the short term, families with moderate fecundity achieved greater long-run reproductive success. This suggests natural selection favored moderate fertility rates, supporting a quantity-quality tradeoff in which parents invested more resources in fewer children.

I've also uncovered evidence that pre-industrial families actively controlled their fertility through birth spacing, challenging traditional Malthusian narratives. This work provides important insights into the demographic transition and demonstrates that even historical populations employed sophisticated fertility control strategies in response to economic conditions.

This research theme examines how historical shocks, resource access, and economic conditions have influenced long-term development paths. My work connects early-life conditions, resource availability, and market dynamics to explain economic transitions and persistent effects that continue to shape modern economies.

Using empirical evidence from historical England and Scandinavia, I've demonstrated that regions experienced a "post-Malthusian" phase where population and income grew simultaneously despite diminishing returns. This research supports transitional growth theories that bridge Malthusian stagnation and modern economic growth, providing insights into the mechanisms driving the Industrial Revolution.

My work on natural resources has challenged traditional "resource curse" narratives by showing that localities closer to oil fields in Brazil enjoy higher per capita income, independent of oil royalties. This suggests "indirect linkage" effects where resource proximity creates positive economic spillovers, informing our understanding of how natural resources can contribute to local economic development.

This research theme focuses on the intersection of health, biology, and economic outcomes. My interdisciplinary work spans from historical health shocks to contemporary medical studies, investigating how biological factors influence both short and long-term wellbeing across different populations.

Through collaboration with medical researchers, I've contributed to understanding how antihypertensive medication affects glaucoma onset, how brain responses correlate with intelligence, and the fertility patterns of specific populations. This research uses advanced statistical methods applied to large-scale medical and population datasets to identify causal relationships in health outcomes.

Historical health research is also a key component of this theme. My work on the English famine of the 1720s demonstrated that early-life adversity caused permanent health damage, with affected individuals experiencing higher mortality risks into adulthood. These findings contribute to our understanding of the lasting impact of health shocks and have implications for how societies should respond to health crises today.