Taxing fat versus behavioural interventions: Multiple discrete–continuous extreme value (MDCEV) models and the PCSHOP randomized trial of shopping behaviour
利用随机试验的超市购物数据，用MDCEV模型比较税收与行为干预对减少饱和脂肪摄入的效果，发现税收结合饮食建议更有效。
• A Multiple Discrete-Continuous Extreme Value (MDCEV) analysis of shopping behaviour data from a randomized controlled trial. • We compare behavioural interventions and taxes on the amount of saturated fat in shoppers’ weekly shopping baskets. • MDCEV models are a potentially useful new tool for analysing food behaviour. Understanding food purchasing behaviours is complex because people make both choices among goods and volumes of those goods that they choose. We use the novel Multiple Discrete-Continuous Extreme Value (MDCEV) model, capable of handling both aspects of behaviour, on real-world food shopping behaviour data from a clinical trial. We compared the impact of providing general dietary advice, general dietary advice plus personalised shopping advice, or taxation, and combinations thereof, on the amount of saturated fat in consumers’ shopping baskets, using simulation. We used supermarket loyalty card data from a randomized controlled trial of 111 adults with raised cholesterol in Oxfordshire (UK). A Danish fat tax simulation alone is less effective than the tax in combination with dietary and shopping advice. These data illustrate the potential of MDCEV models for these behaviours and, by extension, informing food policies.