TY - JOUR
T1 - Climate change and the opportunity cost of conflict
AU - Roche, Kevin R.
AU - Müller-Itten, Michéle
AU - Dralle, David N.
AU - Bolster, Diogo
AU - Müller, Marc F.
N1 - Publisher Copyright:
© 2020 National Academy of Sciences. All rights reserved.
PY - 2020/1/28
Y1 - 2020/1/28
N2 - A growing empirical literature associates climate anomalies with increased risk of violent conflict. This association has been portrayed as a bellwether of future societal instability as the frequency and intensity of extreme weather events are predicted to increase. This paper investigates the theoretical foundation of this claim. A seminal microeconomic model of opportunity costs-a mechanism often thought to drive climate-conflict relationships- is extended by considering realistic changes in the distribution of climate-dependent agricultural income. Results advise caution in using empirical associations between short-run climate anomalies and conflicts to predict the effect of sustained shifts in climate regimes: Although war occurs in bad years, conflict may decrease if agents expect more frequent bad years. Theory suggests a nonmonotonic relation between climate variability and conflict that emerges as agents adapt and adjust their behavior to the new income distribution. We identify 3 measurable statistics of the income distribution that are each unambiguously associated with conflict likelihood. Jointly, these statistics offer a unique signature to distinguish opportunity costs from competing mechanisms that may relate climate anomalies to conflict.
AB - A growing empirical literature associates climate anomalies with increased risk of violent conflict. This association has been portrayed as a bellwether of future societal instability as the frequency and intensity of extreme weather events are predicted to increase. This paper investigates the theoretical foundation of this claim. A seminal microeconomic model of opportunity costs-a mechanism often thought to drive climate-conflict relationships- is extended by considering realistic changes in the distribution of climate-dependent agricultural income. Results advise caution in using empirical associations between short-run climate anomalies and conflicts to predict the effect of sustained shifts in climate regimes: Although war occurs in bad years, conflict may decrease if agents expect more frequent bad years. Theory suggests a nonmonotonic relation between climate variability and conflict that emerges as agents adapt and adjust their behavior to the new income distribution. We identify 3 measurable statistics of the income distribution that are each unambiguously associated with conflict likelihood. Jointly, these statistics offer a unique signature to distinguish opportunity costs from competing mechanisms that may relate climate anomalies to conflict.
KW - Agriculture
KW - Income shock
KW - Microeconomic theory
KW - Rainfall
KW - Violence
UR - http://www.scopus.com/inward/record.url?scp=85078687033&partnerID=8YFLogxK
UR - https://dx.doi.org/10.1073/pnas.1914829117
U2 - 10.1073/pnas.1914829117
DO - 10.1073/pnas.1914829117
M3 - Article
C2 - 31932433
AN - SCOPUS:85078687033
SN - 0027-8424
VL - 117
SP - 1935
EP - 1940
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 4
ER -