NEW YORK (MainStreet) — As we all know by now, the recession cost the U.S. in many ways, from the millions of jobs and homes that were lost to the hundreds of billions of dollars that both the federal and state governments spent to keep the country afloat. But all of this may obscure the other startling loss during the recession years: our nation’s millionaires.

The number of millionaire households increased by 8% in 2010, following a similar increase of 16% in 2009, according to the latest data from Spectrem Group, a research firm covering the affluent market. There were 8.4 million households worth at least $1 million by the end of 2010, up from 7.8 million the year before.

Moreover, the number of super wealthy households have increased significantly as well. Spectrem’s report, which is based on surveys of more than 5,000 affluent households nationwide, finds that the number of households with a net worth of at least $5 million increased by 8% from the year before to 1.06 million in 2010.

“The millionaire comeback continues. After taking a big recession-driven hit in 2008, the U.S. millionaire population staged a second-straight year of growth in 2010, adding 600,000 new millionaires,” said George H. Walper, Jr., president of Spectrem Group.

In 2008, at the peak of the recession, the number of U.S. households with a net worth of $1 million or more declined by 27%, according to Spectrem data, but the new numbers show that even though the economy may still be limping along and some 15 million Americans remain unemployed, the millionaires are coming back strong.

As MainStreet reported previously, much of the reason behind the drastic decline of the wealthy during the recession is that these households were more invested in the stock market and other assets than the rest of the population, causing them to lose a greater proportion of their net worth when the economy tanked. Yet this same investment strategy has also helped many households recover their wealth quickly as the economy once again began to grow.

But even though the number of millionaires has increased, many of these households do not actually consider themselves rich. One recent survey found that 42% of millionaires don’t feel wealthy, and on average, won’t consider themselves wealthy until they have $7.5 million.

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