Heterogenous wealth effects of minimum unit price on purchase of alcohol: Evidence using scanner data

One of the key arguments given to oppose the "sin taxes" is that they are regressive in nature and place disproportionately higher cost on the poor thereby reducing their net wealth. The response to a reduction in net wealth attributed to tax can potentially have significant effects through an increase in alcohol purchase by heavy drinkers reinforcing or even offsetting the direct price or substitution effect of these taxes in reducing alcohol consumption. Comparatively little is known empirically about the net wealth effect associated with changes in alcohol tax policy, and this study aims to help fill this gap in the literature. In this study we aim to estimate how the wealth effects of introducing a minimum unit price (MUP) of A$2.00 per standard drink vary over the distribution (quantiles) of alcohol consumers. The data used in this study is a longitudinal panel of 1,395 households' daily alcohol purchases (scanner data) recorded over a full year. Our analysis involves (i) quantile regression to estimate income elasticity over the distribution of consumption, and (ii) using these elasticities to estimate the potential wealth effects of a hypothetical change in alcohol prices from introducing an MUP policy. We control for consumer demographic characteristics, alcohol product prices and prices of close substitutes, and quarterly seasonal effects. We find that the estimated wealth effect from increasing the price of alcohol under a MUP policy is not significant at any point over the distribution of alcohol consumers. The policy increases per capita tax impact by less than A$5.00 per week for light/moderate consumers (50th-80th quantile) and decreases their daily per capita alcohol consumption by less than 0.02 standard drinks. Wealth effects attributable to an MUP policy are likely to be negligible. Substitution effects of the policy dominate the wealth effects in generating key health related outcomes such as reductions in alcohol consumption.