The Gun-Slave Hypothesis and the 18th Century British Slave Trade

The Gun-Slave Hypothesis is the long-standing idea that
European gunpowder technology played a key role in growing the transatlantic
slave trade. I combine annual data from the Transatlantic Slave Trade Database
and the Anglo-African Trade Statistics to estimate a Vector Error Correction Model
of the 18th century British slave trade that captures four versions
of the Gun-Slave Hypothesis: guns-for-slaves-in-exchange,
guns-for-slaves-in-production, slaves-for-guns-derived and the gun-slave cycle.
Three econometric results emerge. (1) Gunpowder imports and slave exports were
co-integrated in a long-run equilibrium relationship. (2) Positive deviations
from equilibrium gunpowder “produced” additional slave exports. This guns-for-slaves-in-production
result survives 17 placebo tests that replace gunpowder with non-lethal
commodities imports. It is also confirmed by an instrumental variables
estimation that uses excess capacity in the British gunpowder industry as an
instrument for gunpowder. (3) Additional slave exports attracted additional
gunpowder imports for 2-3 more years. Together these dynamics formed a
gun-slave cycle. Impulse-response functions generate large increases in slave
export in response to increases in gunpowder imports. I use these results to explain
the growth of slave exports along the Guinea Coast of Africa in the 18th
century.