As discussed earlier in this chapter, reported revenues do not always equal cash collected from customers because some sales may be on credit. Also, expenses reported on the income statement may not be equal to the cash paid out during the period because expenses may be incurred in one period and paid for in another. Because the income statement does not provide information concerning cash flows, accountants prepare the statement of cash flows to report inflows and outflows of cash. The cash flow statement equation describes the causes of the change in cash reported on the balance sheet from the end of last period to the end of the current period: