Tim Devinney and Donald Siegel write in their recent editorial of the Academy of Management Perspective (Feb 2012, Vol. 26 Issue 1, p 6-11):

Hubbard and Vetter (1996) estimated that fewer than 5% of management studies are subject to any published form of replication, and when this occurs it invariably refutes the initial research. (p.7)

Reference: Hubbard, R., & Vetter, D. E. (1996). An empirical comparison of published replication research in accounting, economics, finance, management, and marketing. Journal of Business Research, 35(2), 153–164.