An examination of retailers’ compliance with the minimum legal drinking (purchasing) age law in Slovenia: A quasi-experimental intervention study

We studied retailers’ MLDA compliance and the potential effectiveness of two interventions meant to improve this. We conducted a non-randomized quasi-experimental study with two experimental groups and one control group. The study was implemented in three stages between December 2018 and June 2019 (Figure 1):

Figure 1

We purposively selected stores from six retail chains in the following six major cities from different Slovene regions: Ljubljana, Maribor, Kranj, Celje, Novo mesto and Koper. All retail chains in our sample (Mercator, Spar, Hofer, Lidl, Tuš and Eurospin) had stores in all selected cities, and shared similar characteristics: they were privately owned, had similar hierarchical structures and sold alcoholic beverages off-premises.

We used a non-randomized sampling technique to select 100 retail stores across the six selected cities (Table 1). We split the sample evenly into three study groups (two intervention groups and one control group). During the communication intervention, we visited 66 stores with an invitation to cooperate. We added the stores that refused to cooperate to the control group. Intervention visits by the Inspectorate were planned for 34 stores. The Inspectorate conducted law enforcement checks in the branches of one retail chain in one city until the purchase of the alcoholic beverage was successful. After a successful purchase, they no longer visited the branches of that specific retail chain in that city. Due to the Inspectorate’s protocol, eight stores were never visited, and we added them to the control group.

The sample was divided into the following three study units (Figure 1): (1) experimental group for the communication intervention; (2) experimental group for the SMI intervention; and (3) control group, without intervention.

The data collection procedure involved quantitative data collection based on the mystery shopping protocol (Figure 1) and included a questionnaire. By following the mystery shopping protocol, we collected data on MLDA compliance before and after the interventions. The mystery shopper was a minor, escorted by an adult observer. In total, 25 people participated as mystery shoppers (aged 16–17 years, average age 16 years) and observers (aged 20–29 years). The parents of the minors who participated as mystery shoppers provided written informed consent. Mystery shoppers and observers were recruited via the Slovene youth organisation No Excuse Slovenia; observers were selected according to their prior experience in the field of alcohol-harm reduction and received mystery shopping training. We ensured in advance that the underage participants followed the dress codes appropriate to their actual age.

To ensure that the results of mystery shopping were comparable, we used the following set protocol: the mystery shopper selected a 0.5-litre can of beer and a snack and tried to make a purchase. If a cashier asked them about their age, the mystery shoppers were instructed to lie and say they were 18 years old. If a cashier asked for an ID, the mystery shoppers were instructed to show their real valid IDs. The observer discreetly monitored the process from a safe distance to avoid being identified as accompanying the purchaser. If the transaction was successful, the observer collected the purchased alcohol. Together with the mystery shopper, the observer filled out a questionnaire immediately after each mystery shopping visit.

The questionnaire included 30 questions about the basic characteristics of the mystery shopper (gender and age), the characteristics of the visited store (name, address, size, date and hour of the visit, number and type of cash registers) and the characteristics of the cashier (gender and approx. age). Seven yes/no questions asked the mystery shopper and the observer to describe the interaction with the cashier (e.g. “Did the cashier ask about the mystery shopper’s age?”, “Did the cashier ask for the mystery shopper’s ID?”). The mystery shopper and the observer were also asked (in an open-ended question) to summarize the interaction with the cashier. The questionnaire included ten additional questions that were not analysed for this article. The questionnaire was used and validated in a previous intervention study (18).

To gain a better understanding of MLDA compliance from a cashier’s perspective, we also conducted 40 additional semi-structured interviews with persons working as cashiers (29 of the participants were also retail managers). We collected this data in November 2019, once quantitative data collection was complete, in the same retail chains and cities to better interpret the quantitative data. For the qualitative inquiry we used a convenience sampling technique and interviewed the cashiers who worked during our visits to the stores, and who gave verbal consent to participate in the interview about MLDA compliance in practice. The length of the interviews varied between five and 50 minutes, with the average length being 12 minutes. The researcher and assistant wrote down notes during the interviews because the respondents did not agree to audio recordings due to the sensitivity of the focal topic. After the interviews, these notes were prepared for the analysis.

In the intervention stage of the study, we carried out communication interventions and interventions with the SMI to increase retailers’ MLDA compliance.

Quantitative data were analysed using univariate and bivariate data analysis techniques. To examine retailers’ MLDA compliance and the effectiveness of the two interventions directed at cashiers in off-premise stores, we closely observed the relationship between the following three variables that are closely related to MLDA compliance: (1) the number of times that alcohol was sold to the underaged mystery shopper, (2) the number of times that a cashier asked about the mystery shopper’s age, and (3) the number of times that a cashier asked to see the mystery shopper’s ID. The data were analysed using IBM SPSS and MS Excel.

The qualitative data collected after the conclusion of the quantitative study was analysed via the descriptive level of thematic analysis, which is the first, basic stage of thematic analysis (27). Two researchers read through the data, identified recurring answers across the data set, agreed on the common issues conveyed by the respondents and summarized the findings in a descriptive report.

The sample for the data analysis consisted of 97 retail stores (one store was excluded from the sample as it closed down between the two measurement stages, and two stores were excluded due to a loss of the completed questionnaires and thus missing values), of which 26 stores received the communication intervention. The SMI visited 26 stores, with the inspector revealing himself on 18 occasions. The control group consisted of 45 stores (for the distribution between cities, see Table 1).

The results of the pre-intervention measures revealed a high rate of alcohol sales to minors (mystery shoppers), indicating low MLDA compliance. As demonstrated in Table 2, the overall rate of alcohol sales to minors was 88.7%, with the figure varying between cities, and the most problematic cities being Novo mesto and Celje (both with a rate of 100%).

Importantly, the results also revealed that in most cases the cashiers did not follow the standard MDLA protocol, which requires them to check the ID of anyone who does not look to be of legal age. Cashiers inquired about the shoppers’ age in 17.5% of cases, and in 23.5% of the cases, they requested to see the ID. In most of these cases they still sold the alcohol to minors: 12 out of 17 purchases were successful after inquiring about the shopper’s age, and 13 out of 23 purchases were successful even after asking to see the ID which showed that the shopped was underage.

The results of the post-intervention measures revealed an overall decrease of 9.3 percentage points in alcohol sales to minors. The total rate of sales to minors dropped to 79.4% (from 88.7%), with the most notable decreases taking place in Maribor, Novo mesto and Celje (Table 3). It should be noted that the number of retail stores differed greatly between cities, and some had a very low number of stores in the sample.

There was a decrease in alcohol sales in all experimental groups and no decrease in the control group (Figure 2). There was a small drop in alcohol sales (by 3.9 percentage points) in the group that received the communication intervention, with successful purchases decreasing from 96.2% to 92.3%. A more significant drop took place in the group that received the intervention by the SMI, with a decrease of 27.7 percentage points in the group where the inspector revealed himself and a decrease of 50 percentage points (from 87.5% to 37.5%) in the group where the inspector remained undercover.

Figure 2

In the post-intervention measurement stage there was also an improvement in cashiers’ MLDA compliance in terms of requesting to see the ID. Overall, the ID requests increased from 23.5% to 30.9%. This improvement was especially evident in the stores that received the intervention by SMI, regardless of whether the inspector revealed himself or not (Figure 3).

Figure 3

After the interventions, we observed an improvement in the refusal of alcohol sales after requesting to see an ID (Figure 4). In the group that received the communication intervention, the number of ID requests followed by refusals of sale increased from 3.8% to 7.7%. In the group that received the SMI intervention, when the inspector revealed himself, the increase was from 5.6% to 33.3%.

Figure 4

The occasions when cashiers, despite checking the minors’ IDs, sold the alcohol decreased from 16.7% to 5.6%. In both of these groups, the occasions when cashiers checked the IDs and still sold the alcohol decreased (Figure 4).

The analysis showed that the correlation between the cashiers’ ID requests and refused alcohol sales was statistically significant in both the pre-intervention measurement stage (χ=31.38, p<.001) and the post-intervention measurement stage (χ=48.42, p<.001).

The analysis of mystery shoppers’ reports on the purchase interaction with cashiers, collected using the open-ended questions, in most cases revealed an absence of MLDA-informed dialogue between the young shoppers and cashiers. Exchanges mostly concerned the price of the purchase after the provision of the receipt. The most concerning observations in the reports were related to situations in which underaged shoppers were asked for their IDs and were still allowed to purchase the alcoholic beverage, regardless of their true ages being revealed. In these cases, the mystery shoppers reported that the cashiers accepted the ID and then (1) either stared at the ID for a while, without realising that the shopper was underaged, or (2) acknowledged the age but sold the alcoholic beverage anyway. In these cases, some cashiers accompanied the illegal sale by saying something to the effect of “Don’t tell on me”.

In instances when cashiers did not ask for an ID but only asked about the age of the young shopper, the mystery shoppers were instructed to say they were 18. In many cases this response sufficed, and the cashier sold the alcohol without asking to see the ID. In other cases, cashiers did ask to see the ID to check the claim of legal age. After learning the mystery shopper’s actual age, they refused to sell the alcoholic beverage. The mystery shoppers also reported that some cashiers were apologetic after refusing the sale of the alcoholic beverage, explaining that they could get in trouble. In some cases, however, the cashiers expressed anger towards the mystery shoppers, sometimes even accusing the young shoppers of trying to get them in trouble.

The analysis of the interviews with the store managers and cashiers about MLDA compliance in practice revealed that retailers received no official training regarding MLDA. The responsibility for emphasizing MLDA compliance falls onto the branch manager. In many cases, the managers delegated the responsibility for complying with the law to the cashiers based on their skills and personal experience. The cashiers reported it was hard to assess the age of the shoppers based on their looks; in many cases, they perceived it as a personal defeat when, after asking for an ID, the young person turned out to be 18 or over. The store managers mostly motivated their employees to comply with MLDA by reminding them of the legal penalties for failing to do so. All the branches received notifications from higher management when there was increased compliance control by the Inspectorate.