The Bureau of Labor Statistics , which is responsible for maintaining the CPI, has long been aware of the different biases identified by the commission, and it carefully and scrupulously adjusts the CPI to root them out. The government's statistical agencies have a history of producing very fine statistical work. Attacking their statistics damages their credibility and clouds the nation's political and economic understanding. Contesting the technical details of the commission's arguments, Dean Baker has pointed out that the CPI could possibly understate inflation. It fails to take account of increased traffic congestion, which raises the cost of commuting.
Consumers do alter their buying habits as new products come into being and lifestyles change.
However, the most noticeable feature of current trends is the systematic substitution of cheaper products. This substitution is an outcome of the now widely recognized squeeze on ordinary household incomes. The commission would point to this as an example of product-substitution bias and claim that the CPI is overstating inflation. Exactly the same argument applies to the issue of outlet-substitution bias. One can also argue that the inferior service customers receive at discount stores represents a loss of quality and thus that discount shopping reduces quality-change bias.