Knowledge that Transforms

We examine how people form social networks among their peers. We use a unique data set that tells us the volume of email between any two people in the sample. The data are from students and recent graduates of Dartmouth College. First-year students interact with peers in their immediate proximity and form long-term friendships with a subset of these people. This result is consistent with a model in which the expected value of interacting with an unknown person is low (making traveling solely to meet new people unlikely), while the benefits from interacting with the same person repeatedly are high. Geographic proximity and race are greater determinants of social interaction than are common interests, majors, or family background. Two randomly chosen White students interact three times more often than do a Black student and a White student. However, placing the Black and White student in the same freshman dorm increases their frequency of interaction by a factor of three. A traditional “linear in group means” model of peer ability is only a reasonable approximation to the ability of actual peers chosen when we form the groups around all key factors including distance, race and cohort.

This paper exploits the variation occurring from the different timing of divorce law reforms across the United States to evaluate how unilateral divorce changed family violence and whether the option provided by unilateral divorce reduced suicide and spousal homicide. Unilateral divorce both potentially increases the likelihood that a domestic violence relationship ends and acts to transfer bargaining power toward the abused, thereby potentially stopping the abuse in extant relationships. In states that introduced unilateral divorce we find a 8–16 percent decline in female suicide, roughly a 30 percent decline in domestic violence for both men and women, and a 10 percent decline in females murdered by their partners.

The independence of editorial content from advertisers' influence is a cornerstone of journalistic ethics. We test whether this independence is observed in practice. We find that mutual fund recommendations are correlated with past advertising in three personal finance publications but not in two national newspapers. Our tests control for numerous fund characteristics, total advertising expenditures, and past mentions. While positive mentions significantly increase fund inflows, they do not successfully predict returns. Future returns are similar for the funds we predict would have been mentioned in the absence of bias, suggesting that the cost of advertising bias to readers is small.

In a laboratory experiment we show that minimum wages have significant and lasting effects on subjects' reservation wages.The temporary introduction of a minimum wage leads to a rise in subjects' reservation wages which persists even after the minimum wage has been removed.Firms are therefore forced to pay higher wages after the removal of the minimum wage than before its introduction.As a consequence, the employment effects of removing the minimum wage are significantly smaller than are the effects of its introduction.The impact of minimum wages on reservation wages may also explain the anomalously low utilization of subminimum wages if employers are given the opportunity of paying less than a minimum wage previously introduced.It may further explain why employers often increase workers' wages after an increase in the minimum wage by an amount exceeding that necessary for compliance with the higher minimum.At a more general level, our results suggest that economic policy may affect people's behavior by shaping the perception of what is a fair transaction and by creating entitlement effects.

There is widespread evidence supporting the conjecture that borrowing constraints have important implications for firm growth and survival. In this paper we model a multiperiod borrowing/lending relationship with asymmetric information. We show that borrowing constraints emerge as a feature of the optimal long-term lending contract, and that such constraints relax as the value of the borrower's claim to future cash flows increases. We also show that the optimal contract has interesting implications for firm dynamics. In agreement with the empirical evidence, as age and size increase, mean and variance of growth decrease, and firm survival increases.

Managers appear to manipulate firm earnings through their characterizations of pension assets to capital markets and alter investment decisions to justify, and capitalize on, these manipulations. Managers are more aggressive with assumed long-term rates of return when their assumptions have a greater impact on reported earnings. Firms use higher assumed rates of return when they prepare to acquire other firms, when they are near critical earnings thresholds, and when their managers exercise stock options. Changes in assumed returns, in turn, influence pension plan asset allocations. Instrumental variables analysis indicates that 25 basis point increases in assumed rates are associated with 5 percent increases in equity allocations.

The release of Enovid in 1960, the first birth control pill, afforded U. S. women unprecedented freedom to plan childbearing and their careers. This paper uses plausibly exogenous variation in state consent laws to evaluate the causal impact of the pill on the timing of first births and extent and intensity of women's labor-force participation. The results suggest that legal access to the pill before age 21 significantly reduced the likelihood of a first birth before age 22, increased the number of women in the paid labor force, and raised the number of annual hours worked.