Appelbaum said the formula was created to help CFOs weigh the costs of investments, such as a new piece of machinery, within their own company, and assumes that the rate of return for one asset can be repeated year over year."The IRR gives you a great big number, but the true value is nowhere near that great big number," Appelbaum said. "As every public pension fund and every finance person knows, this is not money you can take to the bank."IRR is easy to "game," said Eileen Appelbaum , co-director of the C ...