Both academic researchers and political pundits have generally accepted two over-time features of persuasion by partisan media: that the persuasive effects of partisan media might be temporary and decay quickly after a single exposure, and that these effects accumulate from multiple exposures. That effects decay may serve to ameliorate concerns about the broad impact of such media on partisan polarization. Yet the assumption that persuasive effects accumulate may raise larger concerns from real-world repeat exposure. To explore these possibilities, we implement a novel set of multiwave experiments that allow us to examine concerns about media effects over time. We present estimates from three studies suggesting that the persuasive effect of exposure to just a short article or video clip can persist for up to a week. In contrast to this persistence, our results suggest that an experiment adequately powered to detect the cumulative effect from multiple doses of partisan media—let alone one powered to detect cumulative effects among subgroups of the population—would require an unrealistic number of respondents. These cumulative effects are thus difficult to test in an experimental setting with limited resources.

Do minimum wage increases mobilize low-income voters? We use administrative data to measure the effect of minimum wage increases on voting behavior. We merge public records of New York City municipal employee wages to voting records to observe changes in voting by people affected and unaffected by the minimum wage across multiple elections. Difference-in-differences estimates indicate that recent increases in New York's minimum wage increased voter turnout among low-income workers by several percentage points. These findings are robust to a range of specifications and merge approaches. Further, an analysis of county-level panel data from 1980 to 2016 demonstrates that minimum wage increases are associated with increases in aggregate voter turnout across many contexts. These results imply that economic policy can have democratic implications, with minimum wage increases also serving to increase turnout among low-wage workers and make the electorate more representative.

How can we elicit honest responses in surveys? Conjoint analysis has become a popular tool to address social desirability bias (SDB), or systematic survey misreporting on sensitive topics. However, there has been no direct evidence showing its suitability for this purpose. We propose a novel experimental design to identify conjoint analysis's ability to mitigate SDB. Specifically, we compare a standard, fully randomized conjoint design against a partially randomized design where only the sensitive attribute is varied between the two profiles in each task. We also include a control condition to remove confounding due to the increased attention to the varying attribute under the partially randomized design. We implement this empirical strategy in two studies on attitudes about environmental conservation and preferences about congressional candidates. In both studies, our estimates indicate that the fully randomized conjoint design could reduce SDB for the average marginal component effect (AMCE) of the sensitive attribute by about two-thirds of the AMCE itself. Although encouraging, we caution that our results are exploratory and exhibit some sensitivity to alternative model specifications, suggesting the need for additional confirmatory evidence based on the proposed design.

The standard tools of causal inference have been developed to answer simple causal queries which can be easily formalized as a small number of statistical estimands in the context of a particular structural causal model (SCM); however, scientific theories often make diffuse predictions about a large number of causal variables. This article proposes a framework for parameterizing such complex causal queries as the maximum difference in causal effects associated with two sets of causal variables that have a researcher specified probability of occurring. We term this estimand the Maximum Causal Set Effect (MCSE) and develop an estimator for it that is asymptotically consistent and conservative in finite samples under assumptions that are standard in the causal inference literature. This estimator is also asymptotically normal and amenable to the non-parametric bootstrap, facilitating classical statistical inference about this novel estimand. We compare this estimator to more common latent variable approaches and find that it can uncover larger causal effects in both real world and simulated data.

The single shot nature of experiments on the effects of partisan media on public opinion may limit the relevance of estimates that such studies produce for politics and policy. For example, there might be cumulative effects from multiple doses of partisan media such that the combined effect of repeated exposures on political attitudes is much greater than that of a single dose. Similarly, the persuasive effect of partisan media might be temporary and decay quickly after a single exposure. We implement a novel multi-wave experiment that allows us to examine these concerns. We find that the persuasive effects demonstrate substantial durability, decaying only mildly over the course of a week following treatment. Additionally, we find no evidence of cumulative effects of repeated exposure to partisan media, and instead slight moderation. Together, these results suggest that partisan media’s influence on public opinion is persistent, but the additive effects of “filter bubbles” are limited. We appreciate the research assistance of Grace Chao, Henry Feinstein, and Kaitlin Tucci, and funding from the National Science Foundation (SES-1528487) and the Political Experiments Research Lab (PERL) at MIT. ∗PhD student, Department of Political Science, Massachusetts Institute of Technology, zmarko@mit.edu †Kalb Professor, John F. Kennedy School of Government, Harvard University, Matthew Baum@harvard.edu ‡Mitsui Professor, Department of Political Science, Massachusetts Institute of Technology, berinsky@mit.edu §Assistant Professor, Department of Political Science, Boston University, jdbk@bu.edu ¶Associate Professor, Department of Political Science, Massachusetts Institute of Technology, teppei@mit.edu

There is a sizable literature on higher education, both in the United States and beyond, that draws attention to the phenomenon known as grade inflation. We offer an interpretation of grade inflation that turns on the choices students have over academic departments, and we argue that patterns in grades cannot be considered in isolation from the incentives that students have to sort themselves strategically across departments. Our argument draws on a game-theoretic model in which students of varying abilities face a choice between enrolling in a department whose grades are inflated and thus ability-concealing versus enrolling in a department whose grades are ability-revealing. In equilibrium, all grades are high. Nonetheless, what appears to be grade inflation is a result of the fact that the ability-revealing department in our model attracts highly talented students seeking to distinguish themselves from students of lesser ability, who avoid said department because enrolling in it is costly. Our formalization shows how student sorting can confound grades, and it implies that a full understanding of university’s grade distribution requires knowing which departments in the university are ability-concealing and which, in contrast, are ability-revealing.

In March 2012, Hon Hai Precision Industry Company, Ltd.(Hon Hai) announced its investment in the Sharp Corporation (Sharp). The deal was structured in two parts: the first had Hon Hai investing in Sharp, and the second involved Hon Hai founder, chairman, and CEO Terry Guo personally purchasing a stake in Sharp's unprofitable Sakai manufacturing plant. This case explores the dynamics of the deal and specifically focuses on valuation of the investment in the Sakai plant as well as the structure of the deal. It presents a vehicle by which to consider net present value (NPV) calculations and corporate deal structuring.