Deploying statistics
Combat-intensive deployments in Iraq, Afghanistan, and other post-9/11 war zones were blamed for a surge in behavioral and mental health challenges in returning veterans. But a study recently published in a top economics journal by professors at Tufts, Brown, and West Point suggests the phenomenon was mainly caused by another factor: The military allowed more recruits to enlist in the mid-2000s with lower test scores and waivers for felony convictions or other disqualifying conduct. Because newly recruited soldiers were assigned quasi-randomly to units that went on to have different deployment experiences, the researchers were able to determine that combat-intensive deployment did not cause large increases in suicides, deaths from substance abuse, misconduct, incarceration, bad credit scores, or the inability to complete college.
Bruhn, J. et al., “The Effects of Combat Deployments on Veterans’ Outcomes,’’ Journal of Political Economy (forthcoming).
The impersonal case for targeted ads
Restrictions on targeted online advertising are considered a benefit to individual privacy, but they may come at a cost to consumers. Researchers looked at internal data from Facebook and Instagram to analyze what happened after Apple introduced its App Tracking Transparency feature in 2021. This made it so that apps couldn’t track users by default; users had to give explicit consent to share their data. Industries that had been targeting a relatively high proportion of Apple users were hit hard, putting some companies out of business. Smaller advertisers were hit the hardest — and product prices increased.
Deisenroth, D. et al., “Digital Advertising and Market Structure: Implications for Privacy Regulation,’’ National Bureau of Economic Research (July 2024).
Following the money
Just how influential are the biggest donors on congressional candidates? Economists at Cornell University found that when a candidate’s top donor dies, the candidate’s chances of winning the next election drops — and so does their chance of winning the one after that. But this is not caused by the sudden absence of a prominent donor’s direct contributions. Instead, the effect appears to be driven by a drop in super PAC ad spending associated with the donor’s preferred candidate — presumably because the donor was providing unobserved contributions to super PACs, whose donations are not always easily tracked. Candidates who nevertheless won their elections subsequently appeared less focused on issues that had been associated with their deceased top donors, and they voted more closely in alignment with their party.
Battaglini, M. et al., “Unobserved Contributions and Political Influence: Evidence From the Death of Top Donors,’’ National Bureau of Economic Research (July 2024).
Equalizers
A global team of psychologists argues in a new study that economic inequality makes people likelier to use morality-related language, in an effort to restore order and control. The psychologists analyzed billions of posts made on Twitter in the United States from 2012 through 2020. They found that posts made from areas with higher income inequality were more likely to use morality-related words such as “disgust,’’ “bigot,’’ and “respect,’’ even controlling for the religiosity and partisanship of those areas. Similarly, university students around the world made harsher moral judgments about various everyday scenarios if they lived in a country with more inequality as measured by the World Bank or if they simply perceived more inequality in their country. This appeared to be at least partly explained by the greater perceived degradation of cooperation, trust, and shared moral standards.
Kirkland, K. et al., “High Economic Inequality Is Linked to Greater Moralization,’’ PNAS Nexus (July 2024).
Connections
What’s the value to humans of an endangered species? That can’t be determined by a randomized controlled experiment: It would be impractical and unethical to temporarily remove a species from a given ecosystem in order to see what happens to human affairs. Sometimes, though, there are accidental experiments, as when the vulture population in India collapsed in the late 1990s. This was later discovered to be the result of trace amounts of the drug diclofenac, which had been widely administered to farm animals but was fatal to vultures that feasted on those animals’ carcasses. A new study shows that in the areas that lost the scavenging services of vultures, the resulting sanitation problems caused an estimated 5 percent increase in the human death rate, or over 100,000 additional deaths per year.
Frank, E. & Sudarshan, A., “The Social Costs of Keystone Species Collapse: Evidence From the Decline of Vultures in India,’’
American Economic Review (forthcoming).
