AN NBER PUBLICATION
ISSUE: No. 1, January 2023
The Digest
A free monthly publication featuring non-technical summaries of research on topics of broad public interest

In the two decades since US service members first deployed to Iraq and Afghanistan, the suicide rate for veterans, adjusted for age and gender, has risen nearly twice as quickly as that for nonveterans. Inflation-adjusted disability compensation per veteran has more than quintupled, reaching an average of $4,700 in 2021.
A new study using data on the cohorts of military recruits between 2001 and 2011 challenges the widely held belief that these developments, and...

Article
Between 2019 and 2022, the share of index funds with an environmental, social, and governance (ESG) mandate nearly doubled, from 3 percent to 5 percent. ESG mandates instruct funds to consider the environmental and social consequences of potential investments in addition to their expected financial returns. Many financial intermediaries, boards of directors, and corporate executives are acting as if their investors value ESG, but without quantifying the premium...

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Between 1890 and 1950, public school systems in states of the deep South were racially segregated by law. Disenfranchisement of Black voters enabled White-dominated state and local governments to funnel substantially fewer resources to schools for Black students than to those for Whites. One consequence of this relative underinvestment was the emergence of a large pay gap between Black teachers, who worked in schools attended by Black students, and White teachers, who...
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Privately owned and operated airports are prominent examples of companies running traditionally public infrastructure. As of 2020, nearly 20 percent of the world’s airports had been privatized. Private equity (PE), usually through dedicated infrastructure funds, is playing an increasing role in privatization, purchasing 102 airports out of a total of 437 that have ever been privatized.
In All Clear for Takeoff: Evidence from Airports on the Effects of Infrastructure...
Article
Unicorns — startup businesses that are valued at at least $1 billion before going public — essentially did not exist before the 2000s. Their numbers have recently surged. These firms break with the traditional startup trajectory by going public later and at valuations far above those of other startups. They also attract late-stage funding not from venture capitalists but from large institutional investors who are more patient, more open to raising the large sums...
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The social costs of climate change and local pollution depend crucially on the extent to which humans can adapt to extreme environmental conditions. Individuals can adapt in various ways to short-lived adverse environmental conditions, such as elevated air pollution levels. Some may remain indoors or avoid strenuous activities. Others may leave town when pollution is especially bad.
Over the past 15 years, China has built the largest high-speed rail network in the...
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