Estimating Calorie and Nutrient Price Indices in Japan, 1975-2015
研究日本1975-2015年食品价格变化，发现卡路里实际价格下降且脂肪相对膳食纤维价格大幅降低，并与儿童BMI显著相关。
Obesity, often referred to as the epidemic of the twenty-first century, has been rising across the world. Among the many underlying factors, one that has been studied extensively in economics is the price effect, namely, the effect of food prices on body mass index（BMI）. Noting that the BMI of Japanese population remain exceptionally low among high-income countries, we examine the possibility that trends in food prices in Japan differ from those in Western countries. To provide an internationally comparable measure of long-run changes in food prices, we propose calorie- and nutrient-level price indices and estimate these indices using Japanese data from 1975 to 2015. We find that, not only has the price of one calorie fallen in real terms, but the price of fat relative to dietary fiber has declined substantially. Using prefecture-level panel data, we further find significant correlation between childrenʼs BMI and nutrient prices.