Sidak Yntiso’s research while affiliated with University of Rochester and other places

Many large survey courses rely on multiple professors or teaching assistants to judge student responses to open-ended questions. Even following best practices, students with similar levels of conceptual understanding can receive widely varying assessments from different graders. We detail how this can occur and argue that it is an example of differential item functioning (or interpersonal incomparability), where graders interpret the same possible grading range differently. Using both actual assessment data from a large survey course in Comparative Politics and simulation methods, we show that the bias can be corrected by a small number of “bridging” observations across graders. We conclude by offering best practices for fair assessment in large survey courses.

Scholars and policymakers are concerned about the effects of misleading information found on politically conservative social media. Yet, the ability of scholars to causally identify its effects are limited in part by two methodological hurdles when using observational data. First, few studies have a credible strategy for overcoming the issue of selection bias, whereby conservatives are likelier to consume conservative social media. Second, it has been difficult to reliably link social media activity and offline outcomes. To overcome the first problem, our identification strategy exploits quasi-random spatial and temporal differences in conservative social media usage in the lead-up to the 2020 US presidential election. Specifically, the winner-takes-all rules for awarding most states’ electoral votes means that campaigns focus their mobilization efforts only in swing states. This temporarily increased relative political interest - and conservative social media usage - in these states. Second, we use the public release of metadata from Parler, a conservative alternative to Twitter, to reliably identify the geo-location of conservative social media usage across the US during 2020. Using a county-month panel, we show that Parler activity increased more in counties in swing states in the lead-up to the presidential election. We use this as an instrument to estimate a two-stage least-squares model, which shows that greater county Parler activity over 2020 caused more COVID-19 deaths. The findings are robust to the inclusion of county-month viewership ratings of Fox News Channel. Our study demonstrates causally that politically conservative social media has negative consequences for offline outcomes.

While the fiscal and redistributive consequences of democracy is one of the central debates in political economy, most empirical studies analyze this question solely in the context of transitions to democracy. In this paper, we explore the consequences to taxation of democratic reversal using the systematic disenfranchisement of African Americans in the US South between 1880 and 1910. Following the federally-imposed extension of the franchise to the former slaves during Reconstruction (1865–1877), Southern states erected a series of legal restrictions, such as literacy tests and poll taxes, aimed primarily at preventing Southern African Americans from registering to vote. Using an original dataset of local and state taxes and a difference-in-differences estimation strategy, we demonstrate that the adoption of literacy tests for voting eligibility in each state was followed by a significant decline in tax revenues that is highly correlated to the share of each county's population who was African American. We also find that black disenfranchisement led to a shift of the tax burden onto urban counties and a greater reliance on indirect taxation. Our results survive a battery of robustness checks, alternative specifications and additional tests of the redistributionist thesis. The findings are not only consistent with standard models of redistribution following democratization, but also indicate that the elasticity of taxes with respect to enfranchisement is substantial and larger than the one suggested by the cross-national literature.