Study protocol: combining experimental methods, econometrics and simulation modelling to determine price elasticities for studying food taxes and subsidies (The Price ExaM Study)

作者：Wilma Elzeline Waterlander, Tony A Blakely, Nhung Nghiem, Christine Cleghorn, Helen C. Eyles, Murat Genç, Nick Wilson, Yannan Jiang, Boyd Anthony Swinburn, Liana Jacobi, Jo Michie, Cliona Ní Mhurchú · 发表于：BMC Public Health · 年份：2016 · DOI：10.1186/s12889-016-3277-5 · 被引用次数：18 · 研究领域：Obesity, Physical Activity, Diet、Economics of Agriculture and Food Markets、Consumer Attitudes and Food Labeling

BACKGROUND: There is a need for accurate and precise food price elasticities (PE, change in consumer demand in response to change in price) to better inform policy on health-related food taxes and subsidies. METHODS/DESIGN: The Price Experiment and Modelling (Price ExaM) study aims to: I) derive accurate and precise food PE values; II) quantify the impact of price changes on quantity and quality of discrete food group purchases and; III) model the potential health and disease impacts of a range of food taxes and subsidies. To achieve this, we will use a novel method that includes a randomised Virtual Supermarket experiment and econometric methods. Findings will be applied in simulation models to estimate population health impact (quality-adjusted life-years [QALYs]) using a multi-state life-table model. The study will consist of four sequential steps: 1. We generate 5000 price sets with random price variation for all 1412 Virtual Supermarket food and beverage products. Then we add systematic price variation for foods to simulate five taxes and subsidies: a fruit and vegetable subsidy and taxes on sugar, saturated fat, salt, and sugar-sweetened beverages. 2. Using an experimental design, 1000 adult New Zealand shoppers complete five household grocery shops in the Virtual Supermarket where they are randomly assigned to one of the 5000 price sets each time. 3. Output data (i.e., multiple observations of price configurations and purchased amounts) are used as inputs to econometri...