Statistical Assessments of Representational Reforms: A Case Study from Los Angeles
This paper presents a statistical framework for prospectively evaluating electoral reforms by integrating voter file analysis, ecological inference, and redistricting simulations, demonstrating through a Los Angeles case study that adopting multimember districts and eliminating low-turnout primaries yields greater representational equity than simply expanding the city council.
Original paper licensed under CC BY 4.0 (http://creativecommons.org/licenses/by/4.0/). This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer
In the machinery of American democracy, the way a city draws its voting districts acts as a silent filter, determining which voices rise to the surface and which remain submerged. When a city divides itself into areas for electing representatives, the shape and size of those areas can decide whether a community's preferences translate into actual power. This process, known as redistricting, is often complicated by the fact that people do not vote in equal numbers across all groups, and that the rules for choosing winners—whether a simple majority or a more complex ranking system—can change the outcome entirely. For decades, civic leaders and mathematicians have debated how to design these systems so that the government truly reflects the people it serves, a question that becomes urgent whenever a city grows or its demographics shift.
A team of researchers from Claremont McKenna College turned their attention to Los Angeles, a sprawling metropolis of nearly four million people that has long struggled with a unique problem: its city council is remarkably small for its size. Since 1925, the council has consisted of fifteen members, each representing over 250,000 residents. This ratio is the highest among the ten largest cities in the United States, meaning that in Los Angeles, a single councilor speaks for far more people than their counterparts in New York or Chicago. Following a scandal in 2022 involving racist remarks and discussions of manipulating district maps by some council members, a reform commission was formed to rethink how the city governs itself. The researchers were asked to use statistical tools to predict what would happen if the city changed its rules, specifically by adding more council seats, switching to ranked-choice voting, or creating larger districts where multiple representatives are elected at once.
The researchers began by looking at the reality of who actually votes in Los Angeles. They combined official voter records with census data to estimate the racial makeup of the electorate, a necessary step because California does not ask voters to self-identify their race on registration forms. Their analysis revealed a stark disconnect between the city's population and the people who decide its leaders. While Hispanic residents make up nearly half of the city's population, they represent only about a third of the registered voters, and an even smaller share of those who actually show up to vote in primary elections. In contrast, white residents, who make up about 29 percent of the population, are overrepresented in the voting booths, particularly during the low-turnout primary elections that often decide the winners before the general election even begins. This pattern means that the current system effectively silences the preferences of Hispanic and Asian communities, not because they lack numbers, but because they are spread out across the city or do not vote in the specific elections that matter most.
The team then asked a simple question: would simply adding more council seats fix this problem? Many reformers assumed that if the city expanded its council from fifteen members to twenty-one, twenty-five, or even thirty-three, smaller neighborhoods would finally get their own representatives. To test this, the researchers used a computer simulation that generated hundreds of thousands of possible district maps. These maps were drawn to be compact and equal in population, just as real maps must be, but otherwise random. The results were surprising. In these simulations, simply adding more single-member districts did not significantly change the balance of power. The number of districts where white voters held a majority, or where Hispanic voters held a majority, remained roughly the same regardless of whether the council had fifteen seats or thirty-three. The simulations suggested that without changing the voting rules, a larger council would likely just replicate the same imbalances found in the current system.
The researchers then explored a different approach: eliminating the primary election entirely and replacing it with a single general election where voters rank their candidates in order of preference. This method, known as ranked-choice voting, allows a candidate to win without needing a majority in a low-turnout primary. When the team simulated this change, they found that it would make the electorate more representative by ensuring that the final winner reflects the broader city rather than just the primary voters. However, even this reform had limits when applied to single-member districts; it improved fairness but did not fully solve the problem of geographic dilution for dispersed communities like Asian Angelenos.
The most significant improvement came from a proposal to combine a larger council with a different type of district. Instead of one representative per district, the researchers modeled a system where three representatives are elected from a single, larger district using proportional ranked-choice voting. In this system, a candidate needs only about 25 percent of the vote to win a seat, rather than the 50 percent required to win a single-member district. The simulations showed that this change would allow minority communities to elect representatives of their choice much more reliably. For example, in a three-member district, a Hispanic community that makes up 30 percent of the voters could likely elect one representative, whereas in a single-member district, that same group would rarely have enough votes to win a majority. This structure also ensured that voters living in apartment buildings, who are often renters and tend to vote differently from homeowners, would not be shut out of representation. The simulations indicated that under this system, it would be nearly impossible to draw a map that completely excluded these groups, whereas under the current single-member system, such exclusion was a frequent possibility.
The study concluded that while expanding the city council is a logical step given the city's growth, doing so without changing the voting system would likely fail to improve representation for underrepresented communities. The researchers found that the path to a more equitable government lies not just in adding more seats, but in changing how those seats are filled. By moving to a system of multi-member districts elected through ranked-choice voting, Los Angeles could create a council where the diversity of the city is mirrored in the diversity of its leaders. Although the city's charter reform commission ultimately recommended expanding the council and adopting ranked-choice voting, they stopped short of proposing the multi-member district model, leaving the city to consider these complex trade-offs in the years ahead. The work of the researchers provides a clear, data-driven map for any city facing similar questions, showing that the geometry of democracy is as important as the numbers of the people it serves.
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