Election-Betting Market Seen Plagued by Same Flaws in Past Votes

As the 2024 U.S. presidential election nears, prediction markets have become a popular tool for forecasting the outcome. However, a closer look at the history of election betting markets reveals a pattern of manipulation and inaccuracy that could cast doubt on their reliability.

Prediction markets, such as Polymarket and Kalshi, allow users to bet on the outcome of political events, with odds reflecting the perceived likelihood of different outcomes. In theory, these markets should provide a more accurate reflection of public sentiment than traditional polls, as they aggregate the collective wisdom of many individuals. However, a closer examination of past election betting markets reveals a number of flaws that have led to inaccurate predictions and market manipulation.

One of the most notable examples of market manipulation in election betting markets occurred during the 2016 Brexit referendum. Throughout the campaign, bookmakers gave very long odds on the chance of Brexit, suggesting that the U.K. was unlikely to leave the European Union. However, on the day of the vote, the odds were significantly longer, with some bookies offering odds of 10/1 on Brexit. As it turned out, the bookies were wrong, and the U.K. voted to leave the EU.

A similar pattern emerged in the 2016 U.S. presidential election, where the betting market favored Hillary Clinton over Donald Trump. Despite the close race indicated by traditional polls, the betting market gave Clinton a significant lead, with some bookies offering odds of 8/11 on a Clinton victory. However, Trump ultimately won the election, and the betting market was proven wrong once again.

The 2020 U.S. presidential election also saw a significant divergence between the betting market and traditional polls. Throughout the campaign, the betting market favored Donald Trump, with some bookies offering odds of 6/4 on a Trump victory. However, the election was ultimately won by Joe Biden, and the betting market was once again proven wrong.

The history of election betting markets is littered with examples of manipulation and inaccuracy. In the 2012 U.S. presidential election, the betting market at InTrade consistently predicted that Mitt Romney would beat Barack Obama, despite the fact that Romney ultimately lost the election. Similarly, in the 2004 U.S. presidential election, the betting market at Betfair suddenly swung in favor of a John Kerry victory on the day of the vote, only to be proven wrong when George W. Bush was ultimately re-elected.


The question remains: why are election betting markets so susceptible to manipulation and inaccuracy? One possible explanation is that these markets are often dominated by a small number of high-stakes bettors, who can influence the odds by placing large bets. Additionally, the lack of transparency in these markets can make it difficult to detect and prevent manipulation.


To address these issues, regulators and market operators should consider implementing a number of measures to improve the integrity of election betting markets. These could include increasing transparency, limiting the size of bets, and requiring bettors to disclose their identities. Additionally, regulators should work with market operators to establish clear guidelines on market manipulation and enforce penalties for violations.

In conclusion, while election betting markets can provide valuable insights into public sentiment, they are also susceptible to manipulation and inaccuracy. To ensure the integrity of these markets, regulators and market operators must take steps to address these issues and prevent future manipulation. By doing so, they can help to ensure that election betting markets provide a more accurate reflection of public sentiment and help to inform political decision-making.