Rejecting Ethnic Pandering in Urban Africa: A Survey Experiment on Voter Preferences in Nairobi, Kenya

Ethnic pandering, in which candidates promise to cater to the interests of coethnic voters, is presumed to be an effective strategy for increasing electoral support in Africa’s emerging multiethnic democracies. However, ethnic political mobilization may be disdained by citizens for its divisive and polarizing effects, particularly in urban areas. As a result, pandering may fall on deaf ears among Africa’s urban voters. This study examines how voters in Kenya’s capital city, Nairobi, respond to ethnic pandering using data from a vignette experiment conducted in 2015 and a replication study implemented in 2016. Results show that respondents are more supportive of candidates who make ethnically inclusive rather than targeted appeals, regardless of whether the candidate is identified as a coethnic. We propose that the results are driven by a broad distaste among urban voters for parochial politics, rather than by strategic calculations related to candidate viability.

Commodity Shocks and Incumbency Effects

Why do incumbents enjoy an electoral advantage in some political settings but suffer from a disadvantage in others? We propose a novel explanation linking variation in incumbency effects with exogenous commodity shocks. While voters attempt to sanction incumbents for economic performance, changes in commodity prices affect their evaluations and condition the electoral fortunes of incumbents vis-à-vis challengers. We test our argument in Brazilian municipalities, combining a plausibly exogenous measure of variation in commodity prices with a close election regression discontinuity design. Our results show that increases in the price of agricultural commodities greatly enhance the prospects of incumbents, while negative shocks exacerbate their incumbency disadvantage, especially in rural municipalities. Further investigation suggests that commodity shocks do not operate via voter learning about candidate quality, changes in the pool of candidates, shifts in voter preferences, or strategic elite investments. Instead, we find suggestive evidence that commodity shocks affect voters' evaluations through their effect on local economic growth.

The nonlinear feedback dynamics of asymmetric political polarization

Using a general model of opinion dynamics, we conduct a systematic investigation of key mechanisms driving elite polarization in the United States. We demonstrate that the self-reinforcing nature of elite-level processes can explain this polarization, with voter preferences accounting for its asymmetric nature. Our analysis suggests that subtle differences in the frequency and amplitude with which public opinion shifts left and right over time may have a differential effect on the self-reinforcing processes of elites, causing Republicans to polarize more quickly than Democrats. We find that as self-reinforcement approaches a critical threshold, polarization speeds up. Republicans appear to have crossed that threshold while Democrats are currently approaching it.

Even More Effort Towards Improved Bounds and Fixed-Parameter Tractability for Multiwinner Rules

Multiwinner elections have proven to be a fruitful research topic with many real world applications. We contribute to this line of research by improving the state of the art regarding the computational complexity of computing good committees. More formally, given a set of candidates C, a set of voters V, each ranking the candidates according to their preferences, and an integer k; a multiwinner voting rule identifies a committee of size k, based on these given voter preferences. In this paper we consider several utilitarian and egailitarian OWA (ordered weighted average) scoring rules, which are an extensively researched family of rules (and a subfamily of the family of committee scoring rules). First, we improve the result of Betzler et al. [JAIR, 2013], which gave a O(n^n) algorithm for computing winner under the Chamberlin Courant rule (CC), where n is the number of voters; to a running time of O(2^n), which is optimal. Furthermore, we study the parameterized complexity of the Pessimist voting rule and describe a few tractable and intractable cases. Apart from such utilitarian voting rules, we extend our study and consider egalitarian median and egalitarian mean (both committee scoring rules), showing some tractable and intractable results, based on nontrivial structural observations.

Algorithmic Techniques for Necessary and Possible Winners

We investigate the practical aspects of computing the necessary and possible winners in elections over incomplete voter preferences. In the case of the necessary winners, we show how to implement and accelerate the polynomial-time algorithm of Xia and Conitzer. In the case of the possible winners, where the problem is NP-hard, we give a natural reduction to Integer Linear Programming (ILP) for all positional scoring rules and implement it in a leading commercial optimization solver. Further, we devise optimization techniques to minimize the number of ILP executions and, oftentimes, avoid them altogether. We conduct a thorough experimental study that includes the construction of a rich benchmark of election data based on real and synthetic data. Our findings suggest that, the worst-case intractability of the possible winners notwithstanding, the algorithmic techniques presented here scale well and can be used to compute the possible winners in realistic scenarios.

Inexperienced or anti-establishment? Voter preferences for outsider congressional candidates

Do US voters prefer inexperienced candidates? Candidates who have never held elected office before have had greater success in recent presidential and congressional elections. However, it could be that voters prefer the type of anti-establishment rhetoric that such candidates use more than the lack of experience itself. We conduct a 2x2 factorial experiment that manipulates a fictitious congressional candidate’s experience and rhetoric toward the political system. Results from a nationally representative Qualtrics sample and two follow-up studies from Mechanical Turk show that respondents evaluate the candidate more positively when he uses anti-establishment rhetoric instead of pro-establishment rhetoric. Though the findings are mixed, we find weak and inconsistent evidence that respondent prefer inexperienced candidates to experienced ones. The results suggest that outsider candidates receive an electoral boost by using anti-establishment messaging, but that candidates’ political résumés matter less to potential voters.