4.5 Causal chains & causal mechanism (3)

Nunn and Wantchekon (2011)
- Unit/Unit of analysis = countries
- Treatment: Slave Trade (1400-1900) [Observation]
- Outcome: Present-day levels of Trust (2005) [Observation]
- Theory: “Within this framework, the hypothesis we test is whether the environment of insecurity caused by the slave trade increased the returns to rules-of-thumb based on mistrust relative to rules-of-thumb based on trust, thus causing a culture of greater mistrust to develop.The natural question that we face, though, is why we expect to find evidence of increased mistrust among the descendants of those exposed to the slave trade 100 years after its end. […] individuals inherit norms of cooperation from their parents and make political choices (through voting) that determine the quality of domestic institutions. Through this mechanism, norms of cooperation will affect the equilibrium quality of domestic institutions. When there is a negative shock to internal norms of cooperation, the next generation will not only be less trusting, but also will choose institutions with weaker enforcement, resulting in poor behavior and low levels of trust among future generations” (Nunn and Wantchekon 2011 b, 3226)
The longer the time gap between treatment and outcome…
- …the more fuzzy the theory (causal chain).
- …the more likely something else, unrelated happened inbetween.

Nunn, Nathan, and Leonard Wantchekon. 2011b. “The Slave Trade and the Origins of Mistrust in Africa.” Am. Econ. Rev. 101 (7): 3221–52.