Prior to the use of MTM, Enron would have recognized the actual costs of supplying the gas and the actual revenues received from selling the gas in each time period. Using MTM, at the moment a long-term contract was signed, the present value of the stream of future inflows under the contract was recognized as revenues, and the present value of the expected costs of fulfilling the contract was expensed." Changes in value were recognized as additional income or loss(with a corresponding change to the relevant balance sheet account) in subsequent periods