Is Variety the Spice of Life? Implications for Calorie Intake
探讨为何卡路里的收入弹性远低于食品支出弹性，认为随着收入增加，人们对食物多样性的偏好增强，这解释了卡路里需求弹性低，并质疑世界银行关于贫困人口营养会随收入快速改善的观点。
The income elasticity of calories generally is substantially smaller than the income elasticity of food expenditure. One reason may be an increasing concern for food variety as incomes increase. Food variety can be linked with two characteristics of food indifference curves: (1) curvature and (2) location of the curves relative to the axes. Estimates suggest increasing taste for variety as food budgets increase. Therefore, such taste for variety apparently underlies in part the low income elasticities for calorie demand, which in turn cast doubt on the World Bank assertion that the nutrient intakes of poor populations will improve rapidly with income. Copyright 1989 by MIT Press.