The provision, known as “net operating loss,” or NOL, allows a dizzying array of deductions, business expenses, real estate depreciation, losses from the sale of business assets and even operating losses to flow from the balance sheets of those partnerships, limited-liability companies and S corporations onto the personal tax returns of men like Trump. In turn, those losses can be used to cancel out an equivalent amount of taxable income from, say, book royalties or branding deals.
Better still, if the losses are big enough, they can cancel out taxable income earned in other years. Under IRS rules in 1995, net operating losses could be used to wipe out taxable income earned in the three years before and the 15 years after the loss. (The effect of net operating losses on state income taxes varies, depending on each state’s tax regime.):