The turn-of-the-month effect in U.S. equities is found to be so powerful in the (L&S 1988) appear to have been the first to document a turn-of-themonth effect in equity returns, with the turn of the month beginning on the last trading day of the month and ending on the third trading day of the following month. Using the Dow Jones Industrial Average, they found that the four days at the turn of the month accounted for all of the positive return to the DJIA in the 90-year period of 1897-1986. Specifically, in this period, the average cumulative return over the four-day turn of the month was 0.473 percent whereas for the full month, the average cumulative return was 0.349 percent, indicating that returns were, on average, negative over the remaining days of the month. Because the turnof-the-month effect was not their primary concern, L&S did not explore this pattern in depth.We took up the task of examining the turn-ofthe-month effect in detail in the study reported here. For the U.S. market, we used CRSP daily returns for the 80-year period of 1926-2005. As Schwert (2003 noted, return patterns that appear during a particular time period often disappear once they have been discovered or, upon closer scrutiny, turn out not to have existed to begin with. Therefore, and given that the L&S study ends with 1986, an obvious starting point for our analysis was the 19-year period that has transpired since the end of the period they examined. We found that the pattern in returns during the 1987-2005 period is remarkably similar to the pattern in the earlier period.Having established that the turn-of-the-month pattern has persisted in the U.S. equity market during the recent two decades, we turned to the more consequential task of investigating returns during the 80-year interval of 1926-2005 to determine whether the pattern is attributable to certain sets of stocks-small-capitalization or low-price stocks. We then carried out a variety of tests to determine whether the effect results primarily from returns at the turn of the year or at calendar quarterends, whether higher risk at the turn of the month can explain the pattern, and whether U.S. Treasury securities and corporate bonds exhibit a turn-ofthe-month pattern. In addition, we considered whether the volume of trade or the net flow of funds to equity mutual funds supports Ogden's (1990) hypothesis that the turn-of-the-month effect is caused by "regularity in payment" dates, which we call the "payday hypothesis."We also looked for a turn-of-the-month pattern in other countries for hints as to whether the pattern is universal or results from some peculiarity in the U.S. trading structure. As we show, the turn-of-themonth effect is not confined to the United States.
Prior StudiesWe are not the first to expand upon the L&S study. Nearly contemporaneous with L&S was a study by examining several calendaryear effects, including the January, the holiday, and the day-of-the-week effects. They reported that the turn-of-the-month effect occurred in the 1897-1986 period. Hens...