Compiled ByTonya Vinas According to a recent study by Towers Perrin, New York, a company's decision to include stock options expenses in financial statements has no effect on share price. Towers Perrin, a management and human resources consulting firm, tracked the share price of 103 companies 60 days prior to their "expensing options" announcements and 60 days following such announcements. "Once adjusted for general market movement, the average stock price of announcing companies did now show any significant change during the 120 trading days surrounding the declaration," Towers Perrin reports. "Markets are very good at reflecting available information in security prices and were already awash in information about option grants and their economic costs," says Scott Olsen, co-leader of the company's executive compensation consulting practice. "The study notes that in similar past situations, stock markets have ignored accounting and have paid attention to economics -- for example, when examining company accounting choices in areas like inventory, depreciation or business combinations."