Gambling warning labels: Differing effects of message length and message format

Abstract

“Return-to-player” warning labels are used to display the long-run cost of gambling on electronic gambling machines in several jurisdictions. For example, a return-to-player of 90% means that for every $100 bet on average $90 is paid out in prizes. Some previous research suggests that gamblers perceive a lower chance of winning and have a better objective understanding when return-to-player information is instead restated in the “house-edge” format, e.g., “This game keeps 10% of all money bet on average.” Here we test another potential risk communication improvement: making return-to-player messages longer, by clarifying that the information applies only in the statistical long-run. It was suggested that gamblers might understand this message better than the return-to-player at the conclusion of a court case brought against an Australian casino. In this study, Australian participants (N = 603) were presented with either a standard return-to-player message, a longer “return-to-players” message, or a house-edge message. The longer return-to-players message was understood correctly more frequently than the return-to-player message, but the house-edge message was understood best of all. Participants perceived the lowest chance of winning with the longer return-to-players message. The house-edge format appears easiest for gamblers to correctly understand, but longer warning labels might be the best at warning gamblers about the long-run costs of gambling on electronic gambling machines.

Risk communication improvements for gambling: House-edge information and volatility statements.

“…This study extended these results by uniquely showing that a volatility statement further reduced perceived chances of winning for a house-edge message. For rates of objective understanding, house-edge messages were again understood better than standalone return-to-player messages, as has previously been observed for a U.K. sample (Newall et al, 2020a), and also for a return-to-player message plus a volatility statement, as has been observed with an Australian sample (Newall et al, 2020b). An unexpected interaction did occur for rates of objective understanding between message format and the presence of a volatility statement, albeit with little practical effect, as the house-edge-plus-volatility message was correctly understood by 21.3% more gamblers (66.3%) than the return-to-player-plus-volatility message (45.0%).…”

“…An unexpected interaction did occur for rates of objective understanding between message format and the presence of a volatility statement, albeit with little practical effect, as the house-edge-plus-volatility message was correctly understood by 21.3% more gamblers (66.3%) than the return-to-player-plus-volatility message (45.0%). This unexpected pattern of results across the house-edge conditions may be due to a potential ceiling effect with this type of task and recruitment method, as standalone house-edge messages were understood similarly well in previous U.K. (66.5%; Newall et al, 2020a), and Australian samples (79.9%; Newall et al, 2020b).…”

“…This study was preregistered. The preregistration document, materials, analysis script, and data are available (Newall, 2020). The study received ethical approval from the University of Warwick’s Human Research Ethics Committee (HSSREC).…”

“…given standalone return-to-player information (Newall, Walasek, & Ludvig, 2020b). Houseedge information was still understood the best by 79.9% of participants.…”

“…A potential solution brought about by that case is to make return-to-player messages more descriptive, by adding a volatility statement that the relevant statistic is a long-run average which will not necessarily apply in any period of gambling (in about two sentences). A recent study using a sample of Australian consumers found that return-to-player information plus a volatility statement was understood correctly by 63.5% of participants, compared to 52.9% given standalone return-to-player information (Newall et al, 2020b). House-edge information was still understood the best by 79.9% of participants.…”