Valuation of New Goods under Perfect and Imperfect Competition

The Consumer Price Index (CPI) attempts to answer the question of how much more (or less) income does a consumer require to be as well off in period 1 as in period given changes in prices, changes in the quality of goods, and the introduction of new goods (or the disappearance of existing goods). The CPI has not attempted to estimate the effect of the introduction of new goods, despite the recognition of the potential importance of new goods on a cost-of-living index. In this paper I first explain the theory of cost-of-living indices and demonstrate how new goods should be included using the classical theory of Hicks and Rothbarth. The correct price to use for the good in the pre-introduction period is the "virtual" price which sets demand to zero. Estimation of this virtual price requires estimation of a demand function which in turn provides the expenditure function which allows exact calculation of the cost of living index. The data requirements and need to specify and estimate a demand function for a new brand among many existing brands requires extensive data and some new econometric method which may have proven obstacles to the inclusion of new goods in the CPI up to this point. As an example I use the introduction of a new cereal brand by General Mills in 1989-Apple Cinnamon Cheerios. I find that the virtual price is about 2 times the actual price of Apple-Cinnamon Cheerios and that the increase in consumers surplus is substantial. Based on some simplifying approximations, I find that the CPI may be overstated for cereal by about 25 % because of its neglect of the effect of new cereal brands. I then extend the classical Hicks-Rothbarth theory from its implicit assumption of perfect competition to the more realistic situation of imperfect competition among multiproduct firms. When I take account of the effect of imperfect competition. I find that the increase in consumer welfare is only 85 % as high as in the perfect competition case so that the CPI for cereal would still be too high by about 20%. Digitized by the Internet Archive in 2011 with funding from Boston Library Consortium Member Libraries http://www.archive.org/details/valuationofnewgoOOhaus