Research On A Quality Adjustment Method Of Hedonic Price Index Based On Online Data

Quality adjustment is a difficulty in price index construction.The quality adjustment method of hedonic price index has been focused by researchers in academic field owing to its scientificity,while has yielded unsatisfied adjustment effect in the practice of traditional price index,restricted by the deficiencies of data collection in aspect of time-effectiveness and comprehensiveness.With the development of online retail market,the two characteristics of data collection are achievable based on the advantages of online data,such as massiveness,openness,continuity,and instantaneity,theoretically satisfying the data requirements in the quality adjustment method of hedonic price index.On this basis,this study investigates and improves the quality adjustment method of hedonic price index based on online data to increase the accuracy of price index.This study contains four major sections: Section 1 reviews the theories concerning the quality adjustment method of hedonic price index,points out the difficulties faced by the method in the application into traditional price index,and proposes the opportunities brought by online data to the development of the method;Section 2 reviews the theories concerning the quality adjustment method of product price's fixed-effects index and time-product dummy(TPD)index from the time dummy(TD)of hedonic index.Then by analysis on the disadvantages of both,a cost-based quality adjustment method for hedonic price index is proposed.Using fixed-effects model,the hedonic indexes of time-cost dummy(TCD)are constructed.In addition,WS-TCD hedonic index is obtained using window-splice(WS)technology to realize the dynamic quality adjustment of index;in Section 3,the online data of Chinese smartphone are exampled to concretely verify the operability and applicability of TCD hedonic index;Section 4 is an evaluation on the effectiveness of TCD and the WS-TCD hedonic indexes.This study is mainly concluded as follows: first of all,theoretically based on the supply equilibrium theory of hedonic market and cost composition of product,product cost is divided into costs related and irrelevant to characteristics.As constructing price regression model,the cost irrelevant to the characteristics can be included to improve the fitting goodness of hedonic price regression model;secondly,the cost information irrelevant to the characteristics can be eliminated from quality adjustment factors to enhance the quality adjustment sensitivity of index during index construction;thirdly,it is reasonable to set the cost irrelevant to the characteristics as fixed effects under certain preconditions.In the case of inaccessibility of direct cost information,the producers and retailers of product can be categorized according to enterprise developing stage and management-operation mode etc.It is feasible and effective of using category variables to express the cost irrelevant to the characteristics.The main innovations of this study are embodied on the following aspects: firstly,based on the improvement of hedonic price regression model achieved from the perspective of the supply equilibrium theory of hedonic market and cost composition of product,a cost-based quality adjustment method of hedonic price index and TCD hedonic index are proposed to increase the accuracy of price index;secondly,the complete construction and realization of TCD hedonic index are achieved in this study: using the online market of Chinese smart phone as an example,the quality-adjusted indexes are constructed and the dynamic adjustment of the price index quality is realized.