A study of one of the world’s longest-running disaster warning systems—desert locust monitoring—finds surveillance limits damages and generates returns of up to 680 times the investment.
This new study, published on May 18 by the National Bureau of Economic Research as part of its working papers series, measures how valuable early warning systems could be in limiting the damage caused by natural disasters. Using three decades of data, it evaluates one of the earliest and longest-running disaster monitoring systems: monitoring for the desert locust, one of the world’s most destructive agricultural pests.
“A difficulty in assessing those benefits is that when the monitoring succeeds, locust swarms are nipped in the bud and little to no damage occurs… and therefore don’t get reported,” says study coauthor Anouch Missirian, assistant professor at the Toulouse School of Economics and INRAE. The workaround found by the authors is to evaluate what happens when monitoring is temporarily impeded by armed conflicts, as they prevent field workers from surveying the land. Reduced monitoring, combined with favorable locust breeding conditions like a lot of rain, leads to more locust swarms, the study finds. The authors use machine learning methods to construct the locust swarm migratory paths that connect conflict and rainfall in the locusts’ breeding areas to the human populations that experience the swarm outbreaks far away.
“When locust swarms develop, they destroy the crops and pastureland in their path—consuming as much food each day as about 625,000 people,” says study co-author Eyal Frank, an assistant professor at the Harris School of Public Policy. “This leads to food shortages, making locusts a severe threat to food security across Africa, the Middle East and South Asia.”
Stunted growth and child mortality
With less food, children exposed to locust swarms in utero are 18% more likely to experience stunted growth. In utero (pre-birth) exposure also leads to an increased risk of dying before reaching age 5.
This was the case during the last locust outbreak in 2019 when the Yemen civil war led to gaps in locust reporting, which allowed swarms to develop, migrate, and ravage crops. Around 445,000 additional children saw their growth stunted due to locust monitoring failures, with 83 percent of impacted children living in neighboring countries.
Interruption to an early warning system can quickly spiral into a much bigger regional disaster, and often a health crisis. The consequences are also economic: over the long term, a rise in people with stunted growth impacts productivity—decreasing a country’s GDP by about $25 billion per year, the study finds, whereas the costs of maintaining the monitoring system are relatively modest. Indeed for every $1 invested, the surveillance returns up to $680 from improved childhood nutrition alone. There would be additional agricultural and other benefits.
More broadly, the study points to the need for more data to better pinpoint where disasters are likely to occur in order to prepare before they strike—by investing in comprehensive monitoring as well as other interventions and adaptation policies.
For journalists following science topics, this study shows the importance of international coordination on monitoring and control activities for pests and diseases—and preventative funding. While these systems tend to be costly, their absence or failure is much more so. Locust outbreaks are just one example of the type of disaster we could see more of with climate change.
Anouch Missirian is an assistant professor at TSE and INRAE. She is available for video/phone interviews in English and French. If you're interested, please reach out to TSE Press Officer, Caroline Pain at caroline.pain@tse-fr.eu
This news is part of our series “Headline Research”. Each time a TSE researcher publishes a newsworthy study, we’ll let you - journalists - know, and offer you the opportunity to interview the author.
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