Every Monday, the National Bureau of Economic Research, a nonprofit organization made up of some of North America’s most respected economists, releases its latest batch of working papers. The papers aren’t peer-reviewed, so their conclusions are preliminary (and occasionally flat-out wrong). But they offer an early peek into some of the research that will shape economic thinking in the years ahead. Here are a few of this week’s most interesting papers:

Title: “Compulsory Schooling Laws and Formation of Beliefs: Education, Religion and Superstition”

Authors: Naci Mocan, Luiza Pogorelova

What they found: Compulsory schooling laws have led to a reduction in self-declared religiosity, religious activity and belief in superstition in Europe.

Why it matters: Countries that are more educated tend to be less religious. The two characteristics are correlated. But to examine whether more education causes a decline in religiosity, researchers look for an exogenous change (that is, something external and unrelated) in education, and then examine the change in religiosity before and after. In the 1960s and 1970s, several European countries enacted compulsory schooling reforms. These laws required more education for young people; in Germany, for example, the minimum for schooling was raised from eight years to nine. Using data from the European Social Survey, the authors of this paper find that for 11 countries with such laws, a trend develops: With more compulsory schooling, the rate of self-reported religiosity declines, as do religious activities such as attending services and praying. Using a separate data set, the authors find that superstitious beliefs also wane.

Key quote: “One additional year of schooling reduces individuals’ propensity to pray every day by about 10 percentage points. Likewise, an additional year of full-time education reduces the propensity to attend religious services at least once a week by 10 percentage points. We also find that schooling reduces the propensity to believe in the protective power of lucky charms, and it decreases the tendency to consult horoscopes, and to take into account horoscopes in daily life.”

Data they used: European Social Survey conducted between 2002 and 2013; European Values Survey, 1999 and 2008.

Title: “The Glass Ceiling and The Paper Floor: Gender Differences among Top Earners, 1981–2012”

Authors: Fatih Guvenen, Greg Kaplan, Jae Song

What they found: Female representation among the top 1 percent of earners has increased over time, but women’s total earnings remain significantly below men’s earnings among top performers.

Why it matters: It’s well documented that the highest-earning Americans are making more money. But the gender composition of these high earners hasn’t been so clear. Using individual earnings data from the Social Security Administration, the authors of this paper find that the “glass ceiling” for top earners has improved over time, but that a significant gap between women and men exists. Among the bottom 99 percent of earners, women make up 49 percent of workers and tally 41 percent of the earnings. But for individuals in the top 1 percent, women made up only 11 percent of total earnings; and for those in the top 0.1 percent, women’s earnings totaled 18 percent. The authors also deconstruct the effect of female labor participation across the entire earnings distribution, but this played little role in explaining the trend. In past years, women were more likely than men to fall out of the group of top earners. But now women are just as likely as men to leave the group of high earners. This “paper floor,” as the authors call it, has firmed over time.

Key quote: “We found that although the share of females among the top 1 percent has increased steadily over the last 30 years, the fraction of females in the top 0.1 percent has barely increased during the last decade, and the gender composition of both top earning groups is still very different from the composition of the bottom 99 percent.”

Data they used: 10 percent representative sample of individual earnings histories from the Social Security Administration covering 32 years.

Title: “Estimating the Value Added of Attending Physicians on Patient Outcomes”

Authors: Jason M. Fletcher, Leora I. Horwitz, Elizabeth Bradley

What they found: The researchers create a method to measure a doctor’s “value added”: a risk-adjusted measure to link patient-health outcomes to doctor performance. Doctors with a value added score at the 75th percentile had patients whose health outcomes were 8 percent better than patients of doctors with a score at the 25th percentile.

Why it matters: Education researchers track teacher performance through methods that isolate an instructor’s effect on pupils. The researchers behind this paper develop a similar methodology for doctors, the likes of which might lead to gains in understanding how the best doctors operate. The metric, value-added, would adjust for the health of the patients at time of admission, so that doctors will not be incentivized to seek out healthier patients.

Key quote: “Our findings provide evidence to support a new method of determining the value added by individual physicians to outcomes of hospitalized patients. Though patient outcomes necessarily also reflect care provided by other team members (e.g., physicians in training, nurses, social workers, physical therapists), we were still able to demonstrate that the value added varies substantially across attending physicians and are highly stable for individual physicians across six-month time periods.”

Data they used: Individual-level data from unique inpatients admitted to Yale-New Haven Hospital in Connecticut between July 1, 2011, and June 30, 2012.