COVID vaccine mandates at US colleges substantially reduced COVID deaths, cases and ICU admissions in the surrounding communities.

Immigration improves the quality of care in nursing homes – "Local increases in immigration lead to fewer falls, less use of restraints, and fewer pressure ulcers among nursing home residents, as well as improvements in other measures of quality of care."

Air filter installations in school boost the educational performance of students (measured by test scores) by reducing their exposure to pollution.

Losing a father has substantial adverse economic long-term effects for sons from non-wealthy background

In 2007, NASCAR switched from leaded to unleaded fuel

Overconfidence in children can be good: 8-11 year olds who are overconfident in their math ability are more likely to graduate from high school and under-confident children are less likely to graduate from college than others with comparable childhood math scores

In the aftermath of Hurricane Maria (2017), there was large-scale Puerto Rican migration into Orlando, Florida

100 additional hours of sunshine during the first six months of life reduces the risk of being obese at age 6 by 2.6 percent

Students who attend culturally enriching field trips are more likely to express greater tolerance for people with different opinions, have an increased desire to consume arts, and have better educational outcomes than otherwise comparable students who did not go on trips [RCT data]

About 20% of 4,154 U.S. job seekers in one study lied about attending or graduating from college

58% of major franchisor contracts include "no poaching" agreements whereby employees for one franchise may not subsequently be employed by an affiliated franchise (i.e

Head Start (a program that provides comprehensive education, health, and nutrition services to children of low-income families) significantly improves test scores for children who are exposed to the program.

Minimum wage increases lead to lower recidivism for released prisoners

Fighting Crime in the Cradle: Food stamp availability in early childhood leads to large reductions in later criminal behavior, study finds.

When few firms dominate a market, wages decline (consistent with the economic theory of monopsony)

Young offenders who are sent to more rehabilitative youth facilities become less likely to reoffend than youngsters who are sent to harsher youth facilities

There is no indication that reductions in school class size has any impact on individuals' long-term educational outcomes and economic outcomes.

Flu vaccination in the U.S. substantially reduces mortality and lost work hours

Toddlers and preschoolers from disadvantaged households who had access to food stamps have significantly better health outcomes at ages 6-16 than similar children who did not have access (the study uses variation in eligibility rules).