Consider the task of dividing a state into k contiguous political districts whose populations must not differ by more than one person, following current practice for congressional districting in the USA. A widely held belief among districting experts is that this task requires at least k − 1 county splits. This statement has appeared in expert testimony, special master reports, and Supreme Court oral arguments. In this article, we seek to dispel this belief. To illustrate, we find plans for several states that use zero county splits, that is, all counties are kept whole, despite satisfying contiguity and 1-person deviation. This is not a rare phenomenon; states like Iowa and Montana admit hundreds, thousands, or tens of thousands of such plans. In practice, mapmakers may need to satisfy additional criteria, like compactness, minority representation, and partisan fairness, which may lead them to believe k − 1 splits to be minimum. Again, this need not be true. To illustrate, we conduct short case studies for North Carolina (for partisan fairness) and Alabama (for minority representation). Contrary to expert testimony and Supreme Court oral arguments from Allen v. Milligan (2023), we find that fewer than k − 1 county splits suffices, even when subjected to these additional criteria. This demonstrates our narrow point that k − 1 county splits should not be assumed minimum and also suggests that districting criteria do not conflict as much as people sometimes believe. The optimization methods proposed in this article are flexible and can assist mapmakers in satisfying them.
more »
« less
This content will become publicly available on March 1, 2026
Political Districting to Minimize County Splits
Political Districting to Minimize County Splits When dividing a state into districts for elections, one traditional criterion is that political subdivisions like counties and cities should not be divided unnecessarily. Some states go as far as to say that the number of county splits should be minimized, but previously there was no scalable exact method for determining this. With new integer programming techniques, Shahmizad and Buchanan exactly compute this minimum number for all states and district types (congressional, state senate, state house) across the USA.
more »
« less
- Award ID(s):
- 1942065
- PAR ID:
- 10579889
- Publisher / Repository:
- INFORMS
- Date Published:
- Journal Name:
- Operations Research
- Volume:
- 73
- Issue:
- 2
- ISSN:
- 0030-364X
- Page Range / eLocation ID:
- 752 to 774
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
In this article, we study the political use of denial-of-service (DoS) attacks, a particular form of cyberattack that disables web services by flooding them with high levels of data traffic. We argue that websites in nondemocratic regimes should be especially prone to this type of attack, particularly around political focal points such as elections. This is due to two mechanisms: governments employ DoS attacks to censor regime-threatening information, while at the same time, activists use DoS attacks as a tool to publicly undermine the government’s authority. We analyze these mechanisms by relying on measurements of DoS attacks based on large-scale Internet traffic data. Our results show that in authoritarian countries, elections indeed increase the number of DoS attacks. However, these attacks do not seem to be directed primarily against the country itself but rather against other states that serve as hosts for news websites from this country.more » « less
-
Abstract The United States approached the COVID‐19 pandemic with inconsistent responses that varied by state. In Florida, legislators passed laws contrary to mitigating the pandemic. These laws included banning county and municipal efforts to control the spread of COVID‐19 through mask mandates, social distancing, and prohibiting vaccination mandates during infectious disease epidemics. Moreover, the Legislature simultaneously prioritized policies of social exclusion, passing bills that constrained the rights of transgender individuals, Black Lives Matter protestors, and educators. In this article, I use the perspectives of critical medical anthropology and “governing through contagion” to examine Florida's COVID‐19 response. I argue the COVID‐19 pandemic provided an opportunity for legislators to obfuscate their political power and advance a politics of social division while simultaneously passing policies that undermined human health. I refer to this process as governingwithcontagion: Using a pandemic as a politically expedient backdrop to conceal power and simultaneously harm human health.more » « less
-
Social scientists have highlighted jail incarceration as an important social problem in the United States. However, few national-level generalizable studies have investigated how the characteristics of communities and their local governments influence jail incarceration, despite jails being an intrinsically community-level institution largely run by county governments. In this paper, we ask how place-based community characteristics, particularly county government characteristics, are associated with jail incarceration. To answer this question, we draw primarily from two literatures, place-based punishment vulnerability and research on the local state, to develop a conceptual framework for analyzing local jail incarceration. We utilize a unique data set that includes primary data collected from county governments across the nation. We examine the extent to which socioeconomic, sociodemographic, and county government characteristics are associated with jail incarceration rates using multivariate regression analysis with state-fixed effects for 1400 counties. We find that elevated jail incarceration rates are found in high-poverty, evangelical counties of mid-level economic health with county governments that have introduced service cuts and have local leaders that engage in carceral entrepreneurship. These findings have important implications for the study of jails across the United States.more » « less
-
null (Ed.)It is commonly believed that, in congressional and state legislature elections in the United States, rural voters have an inherent political advantage over urban voters. We study this hypothesis using an idealized redistricting method, balanced centroidal power diagrams, that achieves essentially perfect population balance while optimizing a principled measure of compactness. We find that, using this method, the degree to which rural or urban voters have a political advantage depends on the number of districts and the population density of urban areas. Moreover, we find that the political advantage in any case tends to be dramatically less than that afforded by district plans used in the real world, including district plans drawn by presumably neutral parties such as the courts. One possible explanation is suggested by the following discovery: modifying centroidal power diagrams to prefer placing boundaries along city boundaries significantly increases the advantage rural voters have over urban voters.more » « less
An official website of the United States government
