Reducing meat and fish consumption in wealthier countries would help mitigate climate change, raising the question of the most effective ways to achieve this. Price influences the food people buy, but to our knowledge no published field study has assessed the impact on sales of experimentally altering the price of meat and vegetarian meal options. We ran an experiment across 106 mealtimes with 13,840 meal selections at a college cafeteria in the University of Cambridge (UK), introducing a small change to the price of vegetarian meals (decreased by 20p from £2.05 to £1.85) and meat meals (increased by 20p from £2.52 to £2.72). Total meal sales did not differ significantly before and after the price change. When controlling for other variables, changing price significantly increased the proportion of vegetarian sales by 3.2 percentage points (p = 0.036). However, there was no significant change in meat sales before and after the price change, although fish sales did decline by 2.8 percentage points (p = 0.010). When analysed by individual diners’ pre-experimental meal choices (N = 325), the price intervention significantly affected only the quartile of diners with the highest prior rates of vegetarian and vegan meal selection (“MostVeg” quartile), who increased their vegetarian meal selection by 13.7 percentage points (p = 0.011). Students mainly pay for meals on their university cards and rarely pay with cash, which may lessen the impact of a price intervention in this context. Our results suggest price changes may be one lever for increasing vegetarian meal consumption. Further field studies are needed to test different price changes, and in non-university populations.

减少较富裕国家的肉和鱼消费量将有助于缓解气候变化，从而提出实现这一目标的最有效方法的问题。价格会影响人们购买的食物，但据我们所知，没有公开的实地研究评估过通过肉类和素食套餐价格的实验性改变对销售的影响。我们在英国剑桥大学的大学食堂对106个用餐时间进行了13840种餐食选择的实验，对素食餐点价格（从2.05英镑下调了20便士，从1.85英镑降低了1.8便士）和肉餐价格（增加了20％）进行了实验降低20便士，从2.52英镑降至2.72英镑）。进餐总销售额在价格变化之前和之后没有显着差异。在控制其他变量时，不断变化的价格显着提高了素食销售比例3.2个百分点（p = 0。036）。然而，尽管鱼类销售确实下降了2.8个百分点（p = 0.010），但是在价格变化前后肉类销售没有显着变化。通过对每个用餐者的实验前膳食选择（N = 325）进行分析，价格干预仅显着影响先前选择素食和纯素食者比例最高的用餐者（“ MostVeg”四分位数），从而增加了他们的素食选择率提高了13.7个百分点（p = 0.011）。学生主要使用大学卡支付餐费，很少使用现金支付，这可能会减轻这种情况下的价格干预的影响。我们的结果表明，价格变化可能是增加素食消费的一种手段。需要对非大学人群进行进一步的现场研究，以测试不同的价格变化。尽管鱼品销售确实下降了2.8个百分点（p = 0.010），但价格变化前后肉类销售没有显着变化。通过对每个用餐者的实验前膳食选择（N = 325）进行分析，价格干预仅显着影响先前选择素食和纯素食者比例最高的用餐者（“ MostVeg”四分位数），从而增加了他们的素食选择率提高了13.7个百分点（p = 0.011）。学生主要使用大学卡支付餐费，很少使用现金支付，这可能会减轻这种情况下的价格干预的影响。我们的结果表明，价格变化可能是增加素食消费的一种手段。需要对非大学人群进行进一步的现场研究，以测试不同的价格变化。尽管鱼品销售确实下降了2.8个百分点（p = 0.010），但价格变化前后肉类销售没有显着变化。通过对每个食客的实验前膳食选择（N = 325）进行分析，价格干预仅显着影响先前素食和纯素食选择率最高的食客（“ MostVeg”四分位数），从而增加了他们的素食选择率提高了13.7个百分点（p = 0.011）。学生主要使用大学卡支付餐费，很少使用现金支付，这可能会减轻这种情况下的价格干预的影响。我们的结果表明，价格变化可能是增加素食消费的一种手段。需要对非大学人群进行进一步的现场研究，以测试不同的价格变化。