The impact of this change is expected to be a reduction of about 0.2 percentage points in the annual rate of increase. Substitution bias - Changes in what is purchased. Substitution bias results from the CPI use of fixed products even though consumer behavior changes rapidly. For example, if the price for beef increased very rapidly, consumers might begin to eat more poultry and the price of beef might therefore have little real effect on their cost of living. Outlet Substitution Bias - Changes in where goods are purchased.
Many consumers now purchase more from discount retailers than was true in the past.
Quality Change Bias - Quality improvement of products. As products become more efficient, durable, and reliable, the expenditure for their use, repair and replacement decreases. New Product Bias - Changes in available products. Products become available at a faster rate than changes in the CPI are made. Home computers, VCRs, microwave ovens, cell phones, cable TV, and many other products are introduced and become a part of the fabric of life more quickly than reflected in CPI changes in purchasing habits.