Nov. 16 (Bloomberg) -- Goldman Sachs Group Inc., the largest U.S. securities firm by market value, said the impact of the slump in credit markets on the economy could reach $2 trillion. Losses related to record U.S. home foreclosures using a ``back-of-the-envelope'' calculation may be as high as $400 billion, Jan Hatzius, chief economist at Goldman in New York, wrote in a report. The effects of the losses on the economy will be amplified because the banks and hedge funds involved have borrowed heavily to finance their investments, Hatzius wrote. If leveraged investors realize half of the potential losses, at $200 billion, they ma]y have to scale back lending by $2 trillion, according to the report. ``A $1 mortgage credit loss could result in a reduction in lending by significantly more than $10,'' Hatzius wrote. ``The likely mortgage credit losses pose a significantly bigger macroeconomic risk than generally recognized.'' In other words : buy some protection because we need to earn some bucks with our specificifically for you tailored structured derivatives - and you can write them off as "cost of hedge" within your balance sheet !