@techreport{NBERw10689,
 title = "Weak and Semi-Strong Form Stock Return Predictability, Revisited",
 author = "Wayne E. Ferson and Andrea Heuson and Tie Su",
 institution = "National Bureau of Economic Research",
 type = "Working Paper",
 series = "Working Paper Series",
 number = "10689",
 year = "2004",
 month = "August",
 URL = "http://www.nber.org/papers/w10689",
 abstract = {This paper makes indirect inference about the time-variation in expected stock returns by comparing unconditional sample variances to estimates of expected conditional variances. The evidence reveals more predictability as more information is used, and no evidence that predictability has diminished in recent years. Semi-strong form evidence suggests that time-variation in expected returns remains economically important.},
}