On the difficulty of calculating the cost of living

Quality of life indexes are popular in the press. But they are not that easy to compute. While one can easily measure how much one has to work for, say, a loaf of bread, quality of life needs to consider a broader basket of goods. Now, you need to define that basket, which may be very different across locations (and across time if the horizon is long enough). It becomes even more difficult if some of the goods are location specific, such as housing.

John Winters points out that housing rents and house values are typically used for this kind of exercise. But house values can be very misleading, as most of the price of a house contains future services and their price, not current ones. Rents, in contrast, only contain the value of current services. An additional problem is that depending on the location the rental and sale markets may be very segregated and thick. Indeed, rentals are typically small and of lower quality. Winters compares rents and house values for US metropolitan areas and finds that they correlate well, but house values exhibit wide dispersion, making them indeed less reliable. He recommends using only rents, even if few rents are available and may not be necessarily representative of the housing stock and market.