The primary industry of DC and its suburbs is Plunder and Pillage the rest of the nation. Apparently they are doing a damn good job of it too! https://www.cnsnews.com/article/national/terence-p-jeffrey/9-20-richest-counties-are-dc-suburbs-virginia-suburbs-beat
9 of 20 Richest Counties Are D.C. Suburbs; Virginia Suburbs Beat Silicon ValleyNine of the 20 richest counties in the United States—when measured by median household income—are suburbs of Washington, D.C., according to data released today by the Census Bureau....