Why the Feldstein-Horioka "puzzle" remains unsolved

We argue that the 40-year-old Feldstein-Horioka "puzzle" should have never been labeled as such. We discuss two problems with the literature. First, we show that the series of investment and saving rates typically used in empirical exercises to test the Feldstein-Horioka thesis are not appropriate. The correct series to properly test it are not collected. Second, we show that the Feldstein-Horioka regression is not a model in the econometric sense, that is, an equation with a proper error term (a random variable). The reason is that by adding the capital account to their regression, one gets the accounting identity that relates the capital account, domestic investment, and domestic saving. This implies that the estimate of the coefficient of the saving rate in the Feldstein-Horioka regression can be thought of as a biased estimate of the same coefficient in the accounting identity, where it has a value of 1. Because the omitted variable is known, we call it pseudo bias. Given that this (pseudo) bias is known to be negative and less than 1 in absolute terms, it should come as no surprise that the Feldstein-Horioka regression yields a coefficient between 0 and 1.