The growing wealth disparity between lawmakers and those they represent means a greater separation in their respective economic experiences, the Post said.
The median net worth of a member of the House rose by more than 2 1/2 times -- to $725,000 in inflation-adjusted dollars from $280,000 -- between 1984 and 2009, the newspaper's analysis of financial disclosures indicated.
During the same period, the wealth of an average U.S. family declined slightly to $20,500 from $20,600, a University of Michigan study indicated.
The year 1984 was chosen as the starting point because it is the earliest year in which consistent wealth statistics are available, the newspaper said.
The comparisons exclude home equity because it is not included in congressional reporting.
Members of Congress have long been wealthier than average Americans, the newspaper said. But the congressional affluence shift has not just increased lawmakers' median wealth, but also shrunk the proportion of representatives who have little besides a home.
In 1984, one in five House members had zero or negative net worth, excluding home equity, and by 2009, that number had dropped to one in 12, the Post's disclosures analysis indicated.