The foundation of fraud detection is what professionals call "information matching"--reconciling all the information supplied by the taxpayer (including Social Security numbers) with the information on W-2s and 1099 (miscellaneous income) forms, not to mention investment income and bank transactions.

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The study was published in the New England Journal of Medicine, which did not reveal, at the time, that some funding came from a group called the Foundation for Lung Cancer, Early Detection, Prevention and Treatment.

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