"A 1996 study by David Ikenberry of Rice University measured the short and long-term performance of stock splits. His research included all the 1,275 companies whose stock split 2-for-1 between 1975 and 1990. Mr. Ikenberry compared the split stocks to a control group of stocks for similar-sized companies in similar sectors that had not split. His results were startling. The split stock group performed 8% better than the control group after one year, and 16% better after three years."
A quote from the second linked story (which pertains to Indian stocks):
"Our research on 30 companies that went for stock splits during January 2001 to May 2010 show that exactly half of them moved up a year after the split while the other half witnessed a drop in price."