Back in October I wrote about trust, describing it as an important lubricant of commerce. I then talked about new research by Omar Al-Ubaydli, Daniel Houser, John V. Nye, Maria Pia Paganelli and Xiaofei Pan. In an experimental setting, they found that subjects primed to think about markets tend to be more trusting than those who are not primed to think about anything in particular.
In sum, I wrote:
Progress depends on the extent of the market, the extent of the market depends on trust, and trust can be facilitated with familiarity with markets.
Now, in the latest issue of the American Economic Review, Nathan Nunn and Leonard Wantchekon present some disturbing new results on trust and the long shadow of slavery:
We show that current differences in trust levels within Africa can be traced back to the transatlantic and Indian Ocean slave trades. Combining contemporary individual-level survey data with historical data on slave shipments by ethnic group, we find that individuals whose ancestors were heavily raided during the slave trade are less trusting today. Evidence from a variety of identification strategies suggests that the relationship is causal. Examining causal mechanisms, we show that most of the impact of the slave trade is through factors that are internal to the individual, such as cultural norms, beliefs, and values.