BackgroundThe increase in gambling advertising around live sports is under scrutiny in the UK. There is a lack of evidence for the impact of television advertising on behaviour, despite this being regulated by the gambling industry. This study explores whether television gambling advertising influences football betting during a live football game.MethodsLongitudinal survey data is collected from a sample of men aged 18–45 in England – recruited in Prolific – over the group stages of the 2022 FIFA Qatar World Cup. Purposive sampling methods are used to ensure that higher-risk gamblers are represented within the dataset. Daily surveys in Qualtrics gather data on the timing of football bets placed on each match day. Bets are grouped into windows around the live game: 60, 30, 15 and 10 minutes. This study employs a quasi-experiment exploiting the pseudo-randomised allocation of football matches, and exogenous variation in television gambling advertising, between ITV (advertising) and BBC (no advertising) during the 2022 FIFA Qatar World Cup. Fixed effects Poisson and Logistic models at the individual (i=365) and match (m=48) level estimate the causal effect of television advertising on betting during the game. Key variables include the number of football bets placed during the game, and a binary variable indicating whether the game was televised on ITV.ResultsWe observe an increased frequency IRR: 1.163 – 1.236,p<0.01 and probabilityOR: 1.220 – 1.326,p<0.01 of betting on football during all windows around live games televised on ITV compared to BBC. Inclusion of safer gambling adverts does not mitigate the effects. Exploratory results suggest a dose-response relationship at the 30-minute window IRR:1.110,p<0.01;OR:1.198,p<0.01, and a positive association between the presence of at least one gambling advert and the frequencyIRR: 1.110–1.219,p<0.01, and probability OR: 1.209 – 1.331,p<0.01 of football betting across all windows around the game.ConclusionThese results indicate that gambling advertising stimulates all betting behaviour, rather than just moving market share between companies. By increasing the overall frequency of football betting in the population, this could increase gambling harms. A policy which restricts this form of advertising might be a valuable part of a wider public health strategy to tackle gambling-related harms. To our best knowledge, this is the first study to use a natural experiment to measure the causal effect of television advertising on gambling behaviour. Given the 2005 Gambling Act review, and international interest in this topic, the results of this study are extremely valuable.