Construction of Consumer Price Index for Income Classes in an Inequal Society

2019 Fiscal Year Final Research Report

• Project/Area Number: 15H03336
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Economic statistics
• Research Institution: Osaka University
• Principal Investigator: Fukushige Mototsugu 大阪大学, 経済学研究科, 教授 (10208936)
• Project Period (FY): 2015-04-01 – 2020-03-31
• Keywords: 経済統計学 / 指数論

Outline of Final Research Achievements

In the previous research on the consumer price index, research on the consumer price facing by different income groups and family characters has been conducted individually. In this research, we propose a method to solve these two problems at the same time by going back to the viewpoint of the change of utility level.
By estimating the expenditure function by income quintile groups, we identify the effects of household head age household characters, and cohort. We also use a polynomial function to estimate the effect of overlapping cohorts. It has been clarified that it is effective to measure the household head age group based on approximation by polynomial or dummy variables. However, the linear expenditure system based on the traditional Stone=Geary type utility function is the easiest to handle. It is also clear that the problem of model selection is important for the progress of research.

Free Research Field

経済統計学

Academic Significance and Societal Importance of the Research Achievements

従来の所得階層別の消費者物価の計測では所得階層別の家計が直面するインフレ率しか計測できなかったものが、同一時点での所得階層別の物価水準を比較することが可能となる。さらに代表的個人のみを想定するようなマクロ経済学の一部の分野を除き、ほぼすべての実証分析において、所得水準や消費水準の時系列データやパネル・データを扱う際に必要とされる消費や所得の実質化の方法について、従来の方法とは全く違う新たな実質化の方法を提案する研究であり、実証分析における実質化の考え方に非常に大きな変化をもたらすと研究である。