Factors associated with purchasing trends of milks and plant-based drinks : An analysis of purchase patterns among Finnish loyalty cardholders

Abstract

Milk has been recognized as an important source of essential nutrients for over centuries. However, consumers are choosing plant-based alternatives due to worries about the environment and health complications like lactose intolerance or milk protein allergy. Plant-based drinks obtained from soy, almond, rice, and oat are becoming more and more popular substitutes for liquid milk because of their improved flavor over the past decade, advantages for animal welfare, and ethical issues. There has been a decline in the consumption of dairy milk in Finland over the last few decades, and the reasons for the decline remain largely unexplored, particularly with regard to the impact of sociodemographic factors on long-term purchasing patterns. This study aims to explore the purchasing patterns of liquid milk and plant-based drinks and how these purchasing patterns are associated with the sociodemographic factors of Finnish loyalty cardholders.

The data for this study came from S Group’s loyalty cardholder customers’ grocery purchases of liquid milks and plant-based drinks from September 2016 to December 2018. Participants included in this study (n = 23,215) answered the background questionnaire, which included information on their sociodemographic characteristics, and it was combined with the automatically accumulated liquid milk and plant-drinks purchase data who had the loyalty of at least 61%. Any customer who had missing data for sociodemographic factors was excluded, and 21,668 customers were selected for further analysis of this study. Monthly purchases of different liquid milks and plant-based drinks were calculated and used to analyze the purchasing patterns. The purchasing volume for liquid milk and plant-based drinks was explored according to the different sociodemographic characteristics of the loyalty cardholders. Linear mixed effects model (LMM) was used by using 28 months as a repeated measure, to examine the association between the monthly purchase and the chosen sociodemographic factors (sex, age, and education). Separate models were built for each predictor including time, the predictor, and their interaction.

Semi-skim and skimmed milk were the most popular choices among Finnish loyalty card holders, while purchases of skim milk were marginally declining. There was a noticeable increase in plant-based drink purchases, indicating a change in customer preferences. Other milk types showed fluctuating trends over time, and whole milk was purchased more during the winter holiday season. Over time, liquid milk purchases decreased (beta = -0.028, p < 0.001) and plant-based drinks purchases increased (beta = 0.011, p < 0.001). Males purchased more liquid milk (beta = 0.683, p < 0.001) and plant-based drinks (beta = 0.800, p < 0.001) than females, but the effect of time on purchased volume is the same for both males and females and no interaction with time and sex. Younger customers (age 18-29) purchased fewer liquid milk products compared with older customers (age 60 or more), but the trend was slightly increasing over time (beta = 0.017, p = 0.04). However, middle-aged customers (age 40-59) dominated the purchasing patterns with a higher volume of liquid milk and plant-based drinks. Customers with a higher level of education purchased fewer liquid milk products and more plant-based drinks meaning that purchasing trend over time differed by education.

In conclusion, this study investigated the associations of sociodemographic factors on the purchasing patterns of liquid milk and plant-based drinks for Finnish loyalty cardholders. The decline in overall liquid milk purchases and the increase in plant-based drink purchases were related to sex, being more educated, and being relatively middle-aged. These patterns might not be generalized to other developing or underdeveloped countries as the dataset was dominated by women, highly educated or middle-aged customers. This provides the opportunity to conduct further research to understand how customer preferences for liquid milk and plant-based drinks will change in the future.