Tag Archives: fallacy

Retiring boomers are buying big houses?! Not really…

A misused statistic can spring from a simple mistake. But when the mistake confirms preconceptions or a seems unlikely it can take hold. If it does both, it can become an urban myth.

“Around one third of boomer retirees are upsizing into larger homes” fits the bill. Those boomers! forever self-indulgent and defiant of convention! Is this really happening? No.

A new study by Merrill Lynch and AgeWave surveyed 3,600 adults, a nationally representative sample that included 2,900 who were 50 or older. It found, among other things, that “pre-retirees who expect to downsize when they retire may be surprised to learn that half (49%) of retirees didn’t downsize in their last move. In fact, three in ten upsized into a larger home.” (Another 19% moved to a home of the same size.)


See the difference? The report cites “retirees … in their last move.” Only retirees who actually moved are included. From there it’s a big jump to “a third of boomer retirees,” as on Tweet declared. Or “Why many retirees are upsizing into larger homes,” as one headline put it.

Census Bureau data for 2009-13 shows that only about 7% of people over 50 move in a given year. It’s not surprising. About 80% are homeowners, many with paid-off mortgages, longtime community ties and family nearby. Among people over 60 who own their homes, fully 45% haven’t moved in at least a decade, according to Census data analyzed through the University of Minnesota’s IPUMS archive.

The study itself carries facts that belie the idea that a third of retirees are upsizing:

— A third of surveyed retirees have no plans to move at all in retirement.

— Households with people over 55 account for just under half (47%) of home renovation spending, and about a third of retiree renovators cited adding an office, upgrading a kitchen or bathroom or “improving curb appeal.”

–Paul Overberg



Torturing the data till it lies

“Top 10 states for left-handers!” “Worst states for tall people” “Best country to travel to if you are 45!”

The Web is ripe with news features like this. Recipe: Assemble a basket of social measures for states or nations. Blend, rank and present as a measure of some condition. They are usually built as galleries of images or pages. Even as a reward for multiple clicks, they rarely offer a reader-friendly at-a-glance list.

The biggest problem with rankings like this: They use grouped data to conclude something about experiences that are much more tightly linked to local and personal factors.

This is the ecological fallacy. Put simply, you often can’t infer something about individuals because you have data about a group of them. This is especially true if the link that’s being claimed is barely plausible.


A simple and famous example: In the 1930 Census, a strong correlation existed between states’ English literacy rates and their shares of foreign-born people. But were immigrants more likely to be literate in English than native-born Americans? No. Census data for individuals showed the opposite, of course – Immigrants were less likely than natives to be literate in English. But immigrants had clustered in states with relatively high literacy rates, so grouped data made them seem more literate than natives.

Another example: In the presidential election of 1968, segregationist George Wallace won the electoral votes of AL, AR, GA, LA and MS. These states had the highest rates of black voters. Should we conclude that blacks voted strongly for Wallace?

States – diverse collections of people acting through laws and policies – exert little or no effect on many conditions in daily life, such as crime. And most social conditions vary within a state far more than they do among states. Data journalists spend a lot of time and sweat trying to get this right by collecting *local* crime rates or  student-pupil ratios before they start probing for patterns.

There are legitimate times to rank states, most obviously on something the state government itself can affect directly, like the climate for startup businesses or the strength of consumer protection laws.

And USA TODAY, has run such lists from content partners. They can be fun, clickable lists. But they really don’t tell us anything about ourselves.

So if your state ranks low as a place to be a coin collector or a Chevy driver, don’t fret.

–Paul Overberg