An evaluation of effects on minimum unit pricing of alcohol

About the study 

A minimum unit price (MUP) for alcohol was introduced by the Welsh Government as part of its wider strategy to try to reduce levels of harmful drinking. A MUP of 50p for alcohol was introduced in Wales from 2nd March 2020. This was intended to increase the price of alcoholic products previously sold or supplied below the minimum price, particularly for cheaper, higher strength products. Retailers could not legally sell an alcoholic drink below the minimum price per unit, including any special offers or promotions.

The study took a longitudinal approach to explore the effects of the policy on retailers, and on the purchasing habits of households. In particular, it explored whether retailers supported the policy, perceived changing patterns of purchasing among their customers, influence on the type of products they stocked, and experience of enforcement and compliance. It also used secondary analysis of data on units of alcohol purchased using comparative interrupted time series data for Wales and England (where a MUP for alcohol has not been introduced) from 2016-2023.   

Findings 

The qualitative findings from the interviews with retailers showed:

• The MUP in Wales was having the desired effect by reducing the sale of cheap, higher-strength alcohol by making products of this type more expensive. As a result, customers were said to buy less of them, and retailers were less likely to stock them. This especially applied to ‘off-trade’ retailers such as shops.
• Retailers showed more support for the policy where they understood it was targeted at harm reduction among the population in general. They showed less support where they mistakenly thought it was targeted at problem drinkers.
• ‘On trade’ retailers, such as pubs, bars and clubs, said they thought the policy created fairer competition between them and ‘off trade’ retailers by preventing the latter selling cheap alcohol.
• Difficulties experienced in calculating promotions, offers and discounts in previous waves of data collection were minimised using the Welsh Government MUP app. The overall picture was of retailers willing to comply with their legal obligations in relation to the MPA.

The quantitative analysis showed:

• There was a statistically significant impact the MUP on the number of alcohol units purchased by households. Initially, there was a marked increase in alcohol purchases in Wales following its introduction, coinciding with the COVID-19 mitigation measures. However, this surge was smaller in Wales than in England, and subsequently, alcohol purchasing declined more rapidly in Wales after the pandemic.

Methodology 

The qualitative component involved interviews with 52 different retailers, across three waves of data collection. 30 interviews were conducted at baseline in 2019/20, around the time of the introduction of the MUP and just before COVID-19 protective measures were introduced. 15 of these interviewees were followed up in at wave two (2022/23), and eight at wave three (2024). 15 new interviewees were recruited at wave two, and eight at wave three due to sample attrition.

The sample was monitored to include on and off trade retailers, and independent and chain stores. We recruited businesses in different parts of Wales, including those in urban or rural locations, and close to the Wales-England border. Major supermarkets were excluded from the sample.

The quantitative analysis used comparative interrupted time series (CITS). It compared alcohol purchasing trends in Wales to those in England, where a MUP was not implemented. To conduct the analysis, we used data on units of alcohol purchased and taken back into the home from Kantar’s World Panel over the 2016-2023 period. 

CITS is a statistical method used to evaluate the impact of an intervention or treatment by comparing the changes in outcomes over time between a group that was exposed to the intervention (Wales) and a comparison group that was not (England). This approach allowed researchers to estimate the effect of the intervention while controlling for underlying trends and external factors influencing both groups, increasing our confidence that any effects found are due to MUP.