Taxpayers in California are four times as likely to be audited by the Internal Revenue Service as those living in other states, according to a study reported by the The New York Times citing a university study of tax data.

Overall, Americans stand a 1-in-150 chance of facing IRS scrutiny this year, the Times said. But data obtained by the Transactional Records Access Clearinghouse, a research arm of Syracuse University, show that in 2005 -- the latest year for which figures are available -- residents in California faced a 1-in-62 chance, compared with 1 in 238 for New Jersey.

Part of the reason for such disparities, the researchers said, was reliance on a 1998 study of taxpayer norms. The IRS' "if formula" flags taxpayers who deviate significantly from those norms. About one-third of 2004 audits were initiated because of the formula, the Times said.

The IRS said another reason for the higher audit ratio in California was that its residents had more income from self-employment and business activities that the IRS found prone to abuse than do residents of other states, the newspaper said. Critics of the IRS call its norms outdated because they were calculated before a boom in self-employment. The tax agency had intended to update its 1998 study in 1995, but congress put an end to the project, according to the Times.

The Syracuse researchers also found that back taxes and penalties were rising for the poor and falling for the rich, in a large part because of a 1999 congressional directive that those claiming earned-income credit be closely monitored.