“Perhaps the feeling that campaign spending must be rising is not due to a significant increase in money coming into the political system, but rather a function of superior information obtained through disclosure and better understanding of how some groups circumvent legal barriers,” Ms. Kolodny writes. “However, present understanding does NOT mean that current money flows are higher than those we understood less well in earlier times.”

Ms. Kolodny’s paper, “Do We Know the Cost of Campaigns in the U.S.?” is a reminder of how the oft-cited data compiled and published by the F.E.C. is not treated the way that, for example, official economic statistics are treated. Among the problems she cites:

The numbers aren’t comparable across time. The F.E.C., and most organizations that rely upon its data, report campaign finance figures in current dollars, not adjusting for inflation. In current dollars, almost every election is more expensive than the last. Some organizations account for this, but many journalists don’t.

Totals don’t account for population changes, either. When the F.E.C. began publishing data, congressional districts had, on average, 469,088 people. Now they have an average population of 710,000, and the costs of communicating with a larger electorate aren’t factored into comparisons between elections.

Some of the money is counted twice. For example, House Speaker John Boehner raises millions of dollars through his own committee and transfers much of it to the National Republican Congressional Committee, the Republican Party’s House organization. Both the transfers from Mr. Boehner’s committee and the N.R.C.C.'s subsequent spending count as expenditures. The same is true when a corporate or labor union political action committee raises $5,000 and gives it to a candidate, who then spends it. The F.E.C. tracks donations and spending, but not specific money; if you gave $200 to a candidate, there’s no specific record of where that money went. Again, some organizations, such as the Center for Responsive Politics, account for this in their calculations, but not everyone does.