It seems like they work hard and don't want to show off too much. Here are the first two paragrahps from an article titled More U.S. millionaires are middle-class
"Sitting on a million but still middle-class? New research has found that more and more Americans worth at least $1 million want luxury goods such as yachts but otherwise lead family-focused, work-oriented lives.
Private wealth specialists Lewis Schiff and Russ Alan Prince found the number of Americans with $1 million to $10 million had risen to 8.4 million households -- or 7.6 percent of U.S. households -- and was growing at 15 percent a year."
At that rate, about half of American households will be millionaire households in 13 or 14 years. Maybe a little longer, since if inflation averages 3% a year, after 13-14 years $1 million will only be worth about $600,000 or $700,000. But since the number of millionaires is growing 15% a year while inflation has averaged just about 3% a year for the last 24 years, it is not just rising prices that is causing the number of millionaires to grow. So if we subtract 3% from 15%, and use a growth rate of 12% a year, it will take 16 or 17 years before half the households are millionaires.