Exxon Mobil

Buried deep in American companies’ securities filings is an indicator for how aggressively they are working to shield their income from the Internal Revenue Service and other tax authorities.

Just how busy are Washington lobbyists these days? Consider this: There are nearly 1,000 fewer of them than there were at this time last year—but their clients are spending just as feverishly as they did a year ago, shelling out $1.6 billion through June 30 alone.