Now, two months before the presidential election, the economy has been invited to the culture wars. In a new paper, Kevin A. Hassett and John R. Lott Jr., economists at the American Enterprise Institute, the conservative research organization in Washington, say they have discovered that economic reporters commit the same archetypal sin: slanting the news unequivocally in favor of the Democrats.

How can a nugget of news like the economy's addition of 308,000 new jobs in March - the biggest monthly gain in about four years - yield a report that The Associated Press labeled "Bond prices tumble on jobs data"? Bias, the researchers suspected.

The two economists combed through 389 newspapers and A.P. reports contained in the LexisNexis database from January 1991 through May 2004, during the administrations of George H. W. Bush, Bill Clinton and George W. Bush. They picked out headlines about gross domestic product growth, unemployment, retail sales and orders of durable goods and classified the headlines' depiction of the economy as either positive, negative, neutral or mixed. Then they crunched some numbers.

They found that Mr. Clinton received better headlines than the two Republican presidents. Even after adjusting the data to compensate for differences in economic performance under the three presidents, the Republicans received 20 to 30 percent fewer positive headlines, on average, for the same type of news, they concluded.

For instance, they said, the unemployment rate in the Clinton administration averaged 5.2 percent, only three-tenths of a percentage point less than it has under George W. Bush. But while 44 percent of Mr. Clinton's headlines on unemployment were positive, only 23 percent of President Bush's headlines on the subject have been upbeat.