http://www.economist.com/news/unite...de-huge-loss-or-concocted-one-taxing-patience "Mr Trump may also have benefited from another peculiarly American generosity: towards property moguls. Since 1986 most taxpayers have been unable to deduct losses which exceed their investment in a business, says Steve Rosenthal of the Tax Policy Centre, another think-tank. Real-estate investors are exempt." "That matters because buildings are particularly good at generating paper losses. Investors can generally claim that non-residential property is depreciating over 39 years, even if its market value in fact rises. In theory, any capital gain is taxed later, when the property changes hands. But investors can avoid such a charge by replacing any building they sell with another of a “like-kind”. When the investor eventually dies and passes on his portfolio, the capital gains are forgotten."