Unfair milk prices? Lessons from a split-sample choice experiment

Purpose: In times of “milk price crises”, “fair” milk prices are repeatedly demanded. Various studies indicate an increased willingness to pay (WTP) for the additional attribute of price fairness. Nevertheless, market shares have been low so far. The purpose of this paper is to discuss three possible reasons for this: low reference prices, socially desirable responses in choice experiments and the lack of justification of the claim “fair” by further attributes. Design/methodology/approach: In a split sample, one group facing alternatives with a higher price range and the other with a lower price range, the consumer’s choices are examined. This study uses a social desirability scale for controlling biases in the stated WTP. In addition, the claim “fair” is complemented with a guaranteed price, grazing, regional production and CO2-reduction. A random parameter logit model specified in WTP space is employed to estimate milk consumers’ (n=480) preferences for “fair” milk. Furthermore, a latent class approach reveals information about the source of preference heterogeneity for fair milk attributes among the two groups of the split sample. Findings: This study finds statistically significant differences between the two price ranges. In the low price range, additional attributes can trigger an additional WTP. In the high price range, there is no statistically significant additional WTP. WTP’s dependence on price levels could explain why the market share for “fair” milk has so far been low. Originality/value: This paper contributes to the study of the effect of split samples in choice experiments. In addition, it promotes the understanding of price fairness in milk and its determinants