Knowledge that Transforms

We study whether people became less likely to switch Medicare prescription drug plans (PDPs) due to more options and more time in Part D. Panel data for a random 20 percent sample of enrollees from 2006--2010 show that 50 percent were not in their original PDPs by 2010. Individuals switched PDPs in response to higher costs of their status quo plans, saving them money. Contrary to choice overload, larger choice sets increased switching unless the additional plans were relatively expensive. Neither switching overall nor responsiveness to costs declined over time, and above-minimum spending in 2010 remained below the 2006 and 2007 levels.

We present results from a “corruption game” (a dictator game modified so that recipients can take a side payment in exchange for accepting a reduction in the overall size of the pie). Dictators (silently) treated to be able to take more of the recipient's tokens, took more of them. They were also more likely to believe that recipients had accepted side payments, even if there was a prize for accuracy. The results favor the hypothesis that people avoid altruistic actions by distorting beliefs about others' altruism. (JEL C72, D63, D64, D83)

We examine whether online learning technologies have led to lower prices in higher education. Using data from the Integrated Postsecondary Education Data System, we show that online education is concentrated in large for-profit chains and less-selective public institutions. We find that colleges with a higher share of online students charge lower tuition prices. We present evidence of declining real and relative prices for full-time undergraduate online education from 2006 to 2013. Although the pattern of results suggests some hope that online technology can “bend the cost curve” in higher education, the impact of online learning on education quality remains uncertain.

The optimal allocation of resources in complex environments—like allocation of dynamic wireless spectrum, cloud computing services, and Internet advertising—is computationally challenging even given the true preferences of the participants. In the theory and practice of optimization in complex environments, a wide variety of special and general purpose algorithms have been developed; these algorithms produce outcomes that are satisfactory but not generally optimal or incentive compatible. This paper develops a very simple approach for converting any, potentially non-optimal, algorithm for optimization given the true participant preferences, into a Bayesian incentive compatible mechanism that weakly improves social welfare and revenue. (JEL D82, H82, L82)

Electricity and water are often subsidized in developing countries to increase their affordability for low-income households. Ideally, such subsidies would create sufficient demand in poor neighborhoods to encourage private investment in their infrastructure. Instead, many regions receiving large subsidies have precarious distribution networks supplying users who never pay. Using a structural model of household electricity demand in Colombia, I predict the change in consumption and profits from upgrading low-quality electricity connections. I show that the existing subsidies, which provide greater transfers to areas with unreliable supply, deter investment to modernize infrastructure. Finally, I analyze alternative programs with stronger investment incentives. (JEL H23, H54, L94, L98, O12, O13)

We model a financial market in which investor beliefs are shaped by representativeness. Investors overreact to a series of good news, because such a series is representative of a good state. A few bad news do not change investor minds because the good state is still representative, but enough bad news leads to a radical change in beliefs and a financial crisis. The model generates debt over-issuance, “this time is different” beliefs, neglect of tail risks, under- and over-reaction to information, boom-bust cycles, and excess volatility of prices in a unified psychological model of expectations.

In many economic, political, and social situations, circumstances change at random points in time, reacting is costly, and reactions appropriate to present circumstances may become inappropriate upon future changes, requiring further costly reaction. Waiting is informative if arrival of the next change has non-constant hazard rate. We identify two classes of situations: in the first, delayed reaction is optimal only when the hazard rate of further changes is decreasing; in the second, it is optimal only when the hazard rate of further changes is increasing. These results in semi-Markovian decision theory provide motivations for building delay into decision systems. (JEL C61, D72, D82, D83, K10, M11)

A seven-year randomized evaluation suggests education subsidies reduce adolescent girls' dropout, pregnancy, and marriage but not sexually transmitted infection (STI). The government's HIV curriculum, which stresses abstinence until marriage, does not reduce pregnancy or STI. Both programs combined reduce STI more, but cut dropout and pregnancy less, than education subsidies alone. These results are inconsistent with a model of schooling and sexual behavior in which both pregnancy and STI are determined by one factor (unprotected sex), but consistent with a two-factor model in which choices between committed and casual relationships also affect these outcomes.

We revisit to what extent the increase in income inequality since 1980 was mirrored by consumption inequality. We do so by constructing an alternative measure of consumption expenditure using a demand system to correct for systematic measurement error in the Consumer Expenditure Survey. Our estimation exploits the relative expenditure of high- and low-income households on luxuries versus necessities. This double differencing corrects for measurement error that can vary over time by good and income. We find consumption inequality tracked income inequality much more closely than estimated by direct responses on expenditures. (JEL D31, D63, E21)

In this paper we analyze elections when voters underestimate the correlation between their information sources (“correlation neglect”). We find that this cognitive bias can improve political outcomes. We show that the extreme beliefs which result from correlation neglect induce some voters to base their vote on information rather than on political preferences. We characterize conditions on the distribution of preferences under which this induces higher vote shares for the optimal policies and better information aggregation. (JEL D72, D83)