01909cam a22002297 4500001000600000003000500006005001700011008004100028100002100069245009500090260006600185490004100251500001900292520100800311530006101319538007201380538003601452710004201488830007601530856003701606856003601643w1833NBER20141022022809.0141022s1986 mau||||fs|||| 000 0 eng d1 aWest, Kenneth D.10aDividend Innovations and Stock Price Volatilityh[electronic resource] /cKenneth D. West. aCambridge, Mass.bNational Bureau of Economic Researchc1986.1 aNBER working paper seriesvno. w1833 aFebruary 1986.3 aThis paper establishes an inequality that may be used to test the null hypothesis that a stock price equals the expected present discounted value of its dividend stream, with a constant discount rate. The inequality states that if this hypothesis is true, the variance of the innovation in the stock price is bounded above by a certain function of the variance in the innovation in the dividend. The bound is valid even if prices and dividends are nonstationary.The inequality is used to test the null hypothesis, for some long term annual U.S. stock price data. The null is decisively rejected, with the stock price innovation variance exceeding its theoretical upper bound by a factor of as much as twenty. The rejection is highly significant statistically. Regression diagnostics and some informal analysis suggest that the results are more consistent with there being speculative bubbles in the U.S. stock market than with a failure of the rational expectations or constant discount rate hypothesis. aHardcopy version available to institutional subscribers. aSystem requirements: Adobe [Acrobat] Reader required for PDF files. aMode of access: World Wide Web.2 aNational Bureau of Economic Research. 0aWorking Paper Series (National Bureau of Economic Research)vno. w1833.4 uhttp://www.nber.org/papers/w183341uhttp://dx.doi.org/10.3386/w1833