We have long since become accustomed to having some economist publicly “explain” a rise in the price index by naming some item(s) in the index that rose in price more than the average increase for the relevant period. This view of things is thoroughly ecumenical – the political orientation of the then-current Administration or of the economist makes no difference. It is as if one explained the cause of a fever by reference to the behavior of the mercury in the thermometer. In the quieter arena of academia, we have become equally inured to the ubiquitous insertion of the letter “P” in macroeconomic equations or graphs to represent the general price level at a moment in time. Alas, the reality of the letter does not confer reality on the concept.