Many of the richest households are clustered in the Northeast, from Washington to Boston. The New York City suburbs around Bridgeport, Conn., including several towns that are hubs for investment firms and hedge funds, have the biggest concentration of 5 percenters. The Silicon Valley area of San Jose is second. With 14 percent of households in the top 5 percent, Washington's ranking is due largely to the predominance of two-income, college-educated households. Almost half of all adults have college degrees, the most in the nation. The region's broad affluence, fueled in part by the outsized role played by the federal government, was barely dented while the rest of the country went through a crippling recession. That has helped fuel a transformation in Washington and its suburbs. More luxury retailers have opened in the choicest neighborhoods, and in most places, housing prices dipped rather than collapsed and are now climbing again. But the higher cost of living that accompanies such widespread prosperity has squeezed the middle class and pushed even longtime residents into more distant suburbs where housing costs less. It also makes it more expensive to do business here, since employers must pay bigger salaries and offer more generous benefits to lure talent, said Jim Dinegar, head of the Greater Washington Board of Trade. "I'd rather be at the top than the bottom, so it's mostly good," he said of the census report, which pinpointed concentrations of the top-earning 5 percent between 2007 and 2011. The census statistics illustrate the degree to which the well-to-do gravitate to big cities and their suburbs along the two coasts. "In places with high property values, the only people who can afford to live there are the ones who are doing well," said William H. Frey, a demographer with the Brookings Institution. A lot of the areas that are on top are suburban enclaves in big metro areas. Suburban Washington exemplifies that. In some jurisdictions, one in five households, or close to it, are in the top 5 percent. Loudoun, Fairfax, Howard, Arlington and Montgomery counties were among the 10 counties nationwide with the biggest percentage in the top tier. Prince William County and the cities of Falls Church, Fairfax and Alexandria also had high concentrations, as did the District. Most are also among the jurisdictions that have the nation's highest median household incomes. Many people whose earnings vault them into the top 5 percent say they do not feel they are in society's most elite layer.