A story published by the Washington Post’s Wonkblog last week made the headline claim that “The McMansion is back, and bigger than ever.”  The article says that new homes are an average of 1,000 feet larger than in 1982, and that the “death of the McMansion” has been highly exaggerated, as have claims that development is shifting to smaller, more urban and more walkable development. The Wonkblog article echoes an 2014 post in CityLab –“The Increasingly Bloated American Dream”–which claimed that “American homes are getting bigger and bigger.”

While the data seem to superficially support this argument, a closer reading shows that the apparent surge in McMansions is actually a bit of a statistical mirage. These analysts have overlooked a key limitation of the reported data. It’s actually the case that American homes are only getting bigger if one believes that people living in multi-family housing either aren’t Americans or don’t have homes.

If instead of looking at the median, we look at the actual number of houses built, a different story emerges. As with all single-family housing, the market for big houses remains depressed—housing starts of 4,000 square feet or more are down 59 percent from the peak and are lower now than they were in 2001.  Homebuilders built 137,000 of these huge homes in 2006, but only 56,000 in 2013, according to the Census Bureau.

The only reason these big houses have increased as a share of total new housing is because the market for affordable, smaller single family homes has done even worse. The smaller yet still catastrophic decline in McMansions is hardly evidence of a growing, or even a continuing consumer love-affair with big houses.

Medians are funny measures—they’re highly dependent on the composition of the population being measured. If the housing market were so bad that only Bill Gates had the wherewithal to build a house, the “median” new home would balloon to 66,000 square feet (the size of his Lake Washington mansion). While that’s an extreme example, that’s the kind of thing that has happened to the U.S. housing market since the bubble days of last decade.

When the housing market collapsed, the bottom fell out. The big decline has been in smaller houses. The apparent popularity of the McMansion is a statistical artifact of the misleading median in a still very depressed housing sector. If anything, the rising median size of new homes is more a testament to the continued growth of income inequality in the U.S., coupled with tougher (i.e. more realistic) lending standards by banks.

This becomes apparent when you look at the actual number of new houses built in the U.S. The growth in the share of new single family homes is not due to some burgeoning increase in the demand for McMansions—rather, it represented the bottom falling out of market for single-family homes. Since the housing bubble peaked in 2007, single-family housing construction is down 66 percent. The construction of 4,000 square foot and larger homes—the McMansions—is down 59 percent. Smaller single-family homes under 1,800 square feet are down 75 percent. Meanwhile, the number of multi-family homes constructed has been increasing steadily, and is now back to pre-recession levels. Multi-family housing now makes up 40 percent of new home starts, up from 20 percent a decade ago. If we recalculated the median new home size including both multi- and single-family homes, the increase in the McMansion share would look much smaller.

We’re far from having what by historical standards would be considered a “healthy” housing market. Total housing constructed over the past five years is lower than any five-year period in the past 50 years. Does anyone believe that if the single-family housing market boomed back to 1.5 million housing starts, that the demand would come proportionately from McMansions? Of course not: the only way to get unit growth in single family housing is by getting households of more modest means back into homeownership—if that ever happens. They will be buying smaller houses.

Unlike the old days of NINJA (no income, no job or assets) lending, where even those with poor credit could qualify for loans, today’s credit standards are much higher. The other key factor has been the demise of the trade-up market. Because most people buy their new homes in significant part with the accumulated appreciation on their existing home, the decline in home values meant that very few middle-income households were in any position to trade-up in the real estate market.

There’s another problem with this median measure: it only looks at single-family housing, not all housing. The one bright spot in the housing market is not in single-family homes, but in multi-family units. By excluding the smaller multi-family homes, this automatically biases the median measure upward.

So in large measure, the only healthy segment of the single-family market is for those with very high incomes. Even here, “health” is a relative thing. Compared to the peak of the housing bubble years, sales of McMansions were lower in 2013 than any year since 2001.

If anything, the growth of the median size of new houses is evidence of the continued and growing impact of income inequality. With growth in incomes occurring mostly among those with the highest incomes, it figures that to the extent there is demand for housing, it’s coming disproportionately from those in the highest income brackets who can afford larger homes, and who qualify for credit.

An accurate measure of the popularity of McMansions would look at the extent to which high-income households are buying large new houses. We don’t have a good annual public data series on wealth by household, but a number of private firms estimate the number of high-net-worth households that form the market for these very large single-family homes. The Spectrem Group has estimated the number of U.S. households with net financial worth of $5 million or more (exclusive of the value of their principal home). By their reckoning there are about 1.24 million such households in the U.S. The number fluctuates from year to year, chiefly due to changes in financial markets.

We can get a good contemporaneous gauge of the popularity of McMansions by dividing the number of new 4,000 plus square foot homes sold by the number of households with a net worth of $5 million or more: call it the McMansion/Multi-Millionaire ratio. (There’s no universally accepted definition of McMansion, but since the Census Bureau reports the number of newly completed single-family homes of 4,000 square feet or larger, most researchers take this as a proxy for these over-sized homes.)

The McMansion to Multi-Millionaire ratio started at about 12.5 in 2001 (the oldest year in the current Census home size series)—meaning that the market built 12 new 4,000 square foot-plus homes for every 1,000 households with a net worth of $5 million or more. The ratio fluctuated over the following few years, and was at 12.0 in 2006—the height of the housing bubble. The ratio declined sharply thereafter as housing and financial markets crashed.

Even though the number of high-net-worth households has been increasing briskly in recent years (it’s now at a new high), the rebound in McMansions has been tepid (still down 59 percent from the peak, as noted earlier). The result is that the McMansion/Multi-Millionaire ratio is still at 4.5–very near its lowest point. Relative to the number of high-net-worth households, we’re building only about a third as many McMansions as we did 5 or 10 years ago. These data suggest that even among the top one or two percent, there’s a much-reduced interest in super-large houses.

There are a couple of key lessons here for thinking about the state of the U.S. housing market. Don’t be fooled by the misleading median, and don’t overlook the big rebound in multi-family housing.