PORK pays. It wins votes.
That will be no surprise to members of Congress. They have long fought hard for ''pork barrel'' projects, federal jobs, and other federal spending in their districts, figuring voters would reward them when the time for reelection arrives.
Now two economists, Steven Levitt and James Snyder Jr., have confirmed the assumption of politicians. For a member of the House of Representatives, they find, the cost of ''buying'' one additional vote amounts to about $14,000 of extra federal spending in his or her district. Or put another way, on average an additional $100 in federal spending per person in a district produces 2 percent more votes for an incumbent.
Pragmatic politicians offer anecdotal evidence of the power of pork to swing elections. Yet political scientists and economists could find little systematic evidence to verify these claims.
In Cambridge, Mass., however, Mr. Levitt of Harvard University and Mr. Snyder of the Massachusetts Institute of Technology devised an ingenious method for measuring the political impact for the nation's 435 representatives of bringing home the bacon. Their work has been published by the National Bureau of Economic Research, also in Cambridge, at a time when a Republican-controlled Congress is demonstrating the bipartisan nature of pork-barrel politics.
''Really extreme conservative Republicans are saying: 'Cut, cut, cut,' in general, and 'spend, spend, spend in my district,' '' Levitt notes. ''We have people pandering for money who shouldn't be ideologically.''
''Jesse Helms,'' Snyder says of the Republican senator from North Carolina, ''is Mr. Fiscal Conservative on everything, except when it comes to tobacco-price supports.'' He voted last month to continue these subsidies.
In February, House Majority Leader Dick Armey (R) of Texas proposed abolishing price supports for peanut farmers. That prompted a sharp retort from a freshman Republican representative, Saxby Chambliss, from the peanut-growing state of Georgia.
The shoe was on the other foot in 1993. Mr. Armey fought unsuccessfully with other Texas legislators from both parties to retain the costly supercollider - located in Texas.
In their study of 1962-90 data, Levitt and Snyder detect no difference between Republicans and Democrats in the impact of federal spending. Republicans didn't especially benefit from defense spending, nor Democrats from additional transfers or grants.
Further, the two explain why representatives fight so hard for keeping military bases and other job-providing federal establishments. They figure that one additional federal job in a district, costing about $70,000, is worth four votes to an incumbent.
The economists did not find any political benefit from Social Security spending, Medicare, Medicaid, and other ''transfer'' spending that voters would consider their right. A representative has little influence on the level of such outlays in a district. But the more discretionary, high-variation spending programs - mostly grants - do offer political benefits. There are more than 1,000 such federal programs, including those for highways, urban development, parks, mass transit, farms, defense, education, and research.
Such spending has a standard deviation (a measure of variance) across districts of $250 per capita, or enough to shift 5 percent of the vote, according to Levitt and Snyder.
Over the past two decades, about 10 percent of all elections involving House incumbents have been won on less than 55 percent of the vote. So the margin of votes provided by federal money could have meant reelection success for these incumbents. Given that only about 5 percent of House incumbents have been defeated over the past two decades, 10 percent represents a very large change in an incumbent's reelection rate.
''When put in the context of a congressional career, the importance of the electoral effect grows even larger,'' the two economists note. It would have decreased from 60 percent to 20 percent the probability of a representative surviving 10 terms. That's about the number of terms a member needs to win chairmanship of a committee with greater power for influencing federal spending - perhaps directing a good chunk home.