Consumer Price Indexes (CPIs) can be subject of heated debate. Plans by the US administration in 2013 to modify the way social security benefits are adjusted for inflation led to protests of federal workers. The new method, which involved a shift from one version of the CPI to another, was designed to make the adjustment more sensitive to consumer substitution behavior. For instance, consumers may shift from blueberries to strawberries if the price of blueberries increases disproportionately – failure to account for such behavior change leads to ‘substitution bias’ in the CPI. However, the move proved deeply unpopular, in part because it was perceived – in Paul Krugman’s words – as “purely and simply, a benefit cut”. Eventually, President Obama dropped the proposal.