Aaron J. Sojourner

Can intensive early childhood intervention programs eliminate income- based cognitive and achievement gaps?

How much of the income-based gaps in cognitive ability and academic achievement could be closed by a two-year, center-based early childhood education intervention? Data from the Infant Health and Development Program (IHDP), which randomly assigned treatment to low-birth-weight children from both higher- and low-income families between ages one and three, shows much larger impacts among low- than higher-income children. Projecting IHDP impacts to the U.S. population’s IQ and achievement trajectories suggests that such a program offered to low-income children would essentially eliminate the income-based gap at age three and between a third and three-quarters of the age five and age eight gaps.

Identification of Peer Effects with Missing Peer Data: Evidence from Project Star

This paper studies peer effects on student achievement among first graders randomly assigned to classrooms in Tennessee’s Project STAR. The analysis uses previously unexploited pre-assignment achievement measures available for 60 percent of students. Data are not missing at random, making identification challenging. The paper develops new ways, given random assignment of individuals to classes, to identify peer effects without imposing other missing-data assumptions. Estimates suggest positive effects of mean peer lagged achievement on average. Allowing heterogeneous effects, evidence suggests lower-achieving students benefit more than higher-achieving students do from increases in peer mean. Further, the bias in a widely used, poorly understood peer-effects estimator is analyzed, implying that caution is warranted in interpreting many peer-effects estimates extant in the literature.

Impacts of Unionization on Quality and Productivity: Regression Discontinuity Evidence from Nursing Homes

Using a regression discontinuity design, the authors of this article examine the effects of nursing home unionization on several labor, establishment, and consumer outcomes. They find negative effects of unionization on staffing levels and no decline in care quality, suggesting positive labor productivity effects. Some evidence suggests that nursing homes in less competitive local product markets and those with lower union density at the time of election experienced stronger union employment effects. Unionization appears to raise wages for a given worker while also shifting the composition of the workforce away from higher-earning workers. By combining credible identification of union effects and firm- and worker-level outcomes over time with measures of market-level characteristics, this study provides important new evidence on many controversial questions in the economics of unions. It also generates evidence from the service sector, which has grown in importance and where evidence has been thin.

Teacher Pay Reform and Productivity: Panel Data Evidence from Adoptions of Q-Comp in Minnesota

This paper studies the impacts of teacher pay-for-performance (P4P) reforms adopted with complementary human resource management (HRM) practices on student achievement and workforce flows. Since 2005, dozens of Minnesota school districts in cooperation with teachers’ unions implemented P4P as part of the state’s Quality Compensation program. Exploiting district variation in participation status and timing, we find evidence that P4P-centered HRM reform raises students’ achievement by 0.03 standard deviations. Falsification tests suggest that gains are causal. They appear to be driven especially by productivity increases among less-experienced teachers.

The Value of Employer Reputation in the Absence of Contract Enforcement: A Randomized Experiment

In two experiments, we examine the effects of employer reputation in an online labor market in which employers may decline to pay workers while keeping the work product. In the first experiment, a blinded worker performs tasks posted by employers with good, bad, or no online reputations. Results confirm that reputation provides information on task completion time and nonpayment, and thereby effective wage rates. In the second experiment, we create multiple employer identities endowed with different exogenously introduced reputations. We find that employers with good reputations attract workers at nearly twice the rate as those with bad reputations with no discernible difference in quality. We interpret these results through the lens of an equilibrium search model in which the threat of a bad reputation deters employers from the abuse of authority even in the absence of contractual protections of workers.

Unionization and Productivity: Evidence from Charter Schools

This paper studies the relationship between teacher unionization and student achievement. Generally stable patterns of teacher unionization since the 1970s have historically presented challenges in measuring the effects of unionization on educational production. However, the blossoming of the charter school sector in recent decades provides fertile ground for study because while most charters are non-union, teachers at some charters have unionized. Using a generalized difference-in-difference approach combining California union certification data with student achievement data from 2003-2012, we find that, aside from a one-year dip in achievement associated with the unionization process itself, unionization does not affect student achievement.

Are Voluntary Agreements Better? Evidence from Baseball Arbitration

This study empirically examines the widespread belief that voluntarily negotiated agreements produce better long-run relationships than do third-party imposed resolutions, such as arbitrator decisions or court judgments. Major League Baseball provides a compelling setting for these analyses because individual performance is well measured, there is the possibility of relationship breakdown, and both voluntary and arbitrator-imposed resolutions routinely occur. Two key outcomes are analyzed: post-resolution player performance and the durability of the club–player relationship. Multivariate analyses of 1,424 salary renegotiations fail to find significant differences in subsequent player performance, but voluntary resolutions are associated with more durable post-resolution club–player relationships.

Trends in Unionization of Nursing Homes

Unionization may have important implications for the delivery of nursing home care, but little is known about this phenomenon. Since 1985, the proportion of nursing home workers covered by union contracts declined from 14.6% to 9.9%. The first national-scale data on facility-level unionization reveals that unions are more common in nursing homes with more residents, in hospital-based or chain-affiliated facilities, and in facilities serving a higher proportion of Medicaid patients. With new federal policy proposals aimed at substantially lowering the cost of organizing workers, policymakers will want to consider the potential impact of nursing home unionization on worker, patient, and market outcomes.