BetData was founded in 2016, the year of the Brexit referendum and Donald Trump's first presidential election. We independently track political betting odds offered by individuals on the Betfair exchange in order to build the web's largest archive of historical political betting odds for academic and research purposes.
Betfair is comfortably the world's most traded and most liquid betting exchange. But they have historically been poor at visualising market odds over time in an accessible format, and as far as we know they do not keep or make available historical betting odds for later analysis.
We think there is a strong case to preserve this data for researchers studying prediction markets, political forecasting, and related fields. So once a minute, we fetch and store the average of back & lay prices and volume information that Betfair publish publicly relating to a range of political events.
Bets on political events matched on the Betfair exchange are interesting because, via their price, they represent at any given moment a real-money-backed crowd consensus on the likelihood of a given outcome.
Unlike financial metrics (such as currencies) that may also track major political events to some extent, betting markets are clear and single-issue.
Betting markets are certainly not perfect predictors of events. There is however some evidence to suggest that betting markets are on average good predictors of political events.
We are in no way officially connected to Betfair, and simply use information that they publish publicly on the website. We do not claim any rights to their trademark, logo or other assets.