Working Paper: NBER ID: w24066
Authors: Murat Iyigun; Nathan Nunn; Nancy Qian
Abstract: This paper provides evidence of the long-run effects of a permanent increase in agricultural productivity on conflict. We construct a newly digitized and geo-referenced dataset of battles in Europe, the Near East and North Africa covering the period between 1400 and 1900 CE. For variation in permanent improvements in agricultural productivity, we exploit the introduction of potatoes from the Americas to the Old World after the Columbian Exchange. We find that the introduction of potatoes permanently reduced conflict for roughly two centuries. The results are driven by a reduction in civil conflicts.
Keywords: Agricultural Productivity; Conflict; Historical Economics
JEL Codes: D74; O13; Q34
Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.
| Cause | Effect |
|---|---|
| Increased agricultural productivity (Q16) | Value of land (Q15) |
| Value of land (Q15) | Incentives for conflict (D74) |
| Increased agricultural productivity (Q16) | Real wages (J31) |
| Real wages (J31) | Opportunity cost of conflict (D74) |
| Conflict (D74) | Long-term equilibrium effect (D59) |
| Introduction of potatoes (N56) | Agricultural productivity (Q11) |
| Agricultural productivity (Q11) | Conflict (D74) |