Tristan Zajonc

Can Foreign Aid Create an Incentive for Good Governance? Evidence from the Millennium Challenge Corporation

The Millennium Challenge Corporation (MCC) awards aid to countries that perform well on a set of independently compiled governance indicators. Proponents of this new form of aid argue that 1) aid will be more effective when given to well-governed countries and 2) countries will respond to such rewards by pursuing sound policies. This paper is the first systematic attempt to evaluate the second hypothesis. By exploiting discontinuities in the MCC rules and reform patterns before and after the MCC was created, we are able to estimate the MCC incentive effect. Even though the MCC is still in its infancy, we find substantial evidence that countries respond to MCC incentives by improving their indicators. Controlling for general time trends, potential recipients of MCC funds improve 25 percent more indicators after the MCC was created than before it. While still to early to make a final assessment, a range of specifications yield similar results. We do not find any corresponding increase in growth rates.

Bayesian Inference for Dynamic Treatment Regimes: Mobility, Equity, and Efficiency in Student Tracking

Policies in health, education, and economics often unfold sequentially and adapt to changing conditions. Such time-varying treatments pose problems for standard program evaluation methods because intermediate outcomes are simultaneously pretreatment confounders and posttreatment outcomes. This article extends the Bayesian perspective on causal inference and optimal treatment to these types of dynamic treatment regimes. A unifying idea remains ignorable treatment assignment, which now sequentially includes selection on intermediate outcomes. I present methods to estimate the causal effect of arbitrary regimes, recover the optimal regime, and characterize the set of feasible outcomes under different regimes. I demonstrate these methods through an application to optimal student tracking in ninth and tenth grade mathematics. For the sample considered, student mobility under the status-quo regime is significantly below the optimal rate and existing policies reinforce between-student inequality. An easy to implement optimal dynamic tracking regime, which promotes more students to honors in tenth grade, increases average final achievement to 0.07 standard deviations above the status quo while lowering inequality; there is no binding equity-efficiency tradeoff. The proposed methods provide a flexible and principled approach to causal inference for time-varying treatments and optimal treatment choice under uncertainty. This article has online supplementary material.

Black Enterprise and the Legacy of Slavery

The 1997 Economic Census data on minority and women-owned businesses reveals distinct cross-state and cross-county differences in ownership characteristics. The breakdown of this data into racial groups provides the opportunity to study the geographical features of black enterprise. As will be seen, both in aggregate and across states and counties, significant differences exist in the prevalence and magnitude of black and white enterprise. I propose a “legacy of slavery” hypothesis to explain these observed differences. Preliminary analysis indicates that this hypothesis has considerable explanatory power. A significant negative relationship exists between the geographical concentration of slavery in 1840 and the current prevalence and magnitude of black-owned enterprise. At the state level, this relationship remains even after controlling for the normal business climate as indicated by white enterprise levels. County level regressions with state fixed-effects yield similar estimated coefficients. In total, I find that the legacy of slavery has reduced the number of black-owned businesses by at least 71,009 and sales by

Do Value-Added Estimates Add Value? Accounting for Learning Dynamics

27.3 billion per year. (Publication Abstract)