What Drives Stock Prices? Identifying the Determinants of Stock Price Movements

In this paper, we show that the data have difficulty distinguishing a stock price decomposition in which expectations of future real dividend growth is a primary determinant of stock price movements from one in which expectations of future excess returns are a primary determinant. The data cannot distinguish between these very different decompositions because movements in the price–dividend ratio are very persistent whereas neither real dividend growth nor excess returns are; most of the information about low-frequency movements in dividend growth and excess returns is contained in stock prices and not the series themselves. We further show that this inability to identify the source of stock price movements is not solely due to poor power and size properties of our statistical procedure, nor does it appear to be due to the presence of a rational bubble.