African adult populations are remarkably tall for the low income levels that prevail at the country level. The average African woman is about 158.5 cm tall, whereas the low gross domestic product per capita would lead us to expect a mean height more similar to the shortest populations in the world, about 4 cm shorter. This is the case in spite of the fact that indicators of socioeconomic status and height are positively correlated within each country. The chapter also shows that the physical stature of African children fit well into the global income–height relationship. Hence, we conclude that the anomaly in the income–height nexus at country level appears to originate between childhood and adulthood. We present evidence for considerable catch-up growth involving entire populations. We discuss possible reasons for this catch-up growth including genetics, and, above all, better nutrition and health conditions during adolescence.

This thesis is formed of three separate essays. The essays are empirical in nature and use the Kagera Health and Development Survey from Tanzania. The survey spans a 19-year period offering a unique opportunity to study many long-run dynamic processes of development in rural Africa.

In the first essay, a version of which was co-authored with Joachim De Weerdt, we use these data to shed light on how mass internal migration changes the nature of informal risk-sharing. By quantifying how shocks and consumption co-move across linked households, our analysis shows that migrants unilaterally insure their extended family members who remain at home. This finding contradicts risk-sharing models based on reciprocity, but is consistent with assistance driven by social norms. Migrants sacrifice three to five per cent of their consumption growth to provide this insurance, which seems too trivial to have a stifling effect on their growth through migration.

The second essay studies the role of exogenous income shocks on long-term migration decisions. The results reveal that temperature shocks cause large fluctuations in household consumption and inhibit long-term migration among men. These findings suggest that liquidity constraints are binding and prevent potential migrants from tapping into the opportunities brought about by internal migration.

The final essay focuses on child nutrition and examines whether under-nourished children are able to recover the height losses later in life. The essay questions the methods used in the existing empirical literature and challenges the conventional view that recovery is nearly impossible after five years of age. The empirical part of the essay documents how puberty offers an opportunity window for recovery in the case of children in Kagera.