The Demand for Varied Diet with Econometric Models for Count Data
用负二项模型分析食品支出和家庭特征如何影响家庭消费的不同食品种类数，发现支出和成员数增加会提高种类数，但增速递减并可能转负。
Abstract A negative binomial model was used to study the relationships between food expenditures, household characteristics, and the demand for different food items. The results show that increases in food expenditure increase the number of food items consumed at home, and the number of food items consumed at home is positively related to increases in the number of household members. This change in the number of food items consumed at home increases at a decreasing rate as household size increases and becomes negative when household size becomes large.