TCS determined its findings by comparing the 15 spending bills in 2008 that have been released to the public to similar measures in 2007.
Unsurprisingly, the group found that with elections looming in just a few short months, House lawmakers have approved roughly 200 more projects than in 2007, leading to an increase of $290 million.
However, across the Capitol the Senate has cut earmarks in spending bills by 16% over the same time period, calling for roughly 200 fewer projects.
Figures for the Senate are based on all the bills that have passed full committee and are awaiting action in both chambers.
TCS found a $426 million drop in funding for the Transportation and Housing and Urban Development spending bill, which they said was due to overspending in previous years, coupled with the precipitous drop in gas tax receipts as motorists drive less.
It should be noted however, that Congress has not completed work on the defense spending bill, a must-pass measure that will surely drive these figures up.
Democratic leaders have indicated they hope to take up the bill in September.
Read more about TCS' study here.