It all started with an article by Edmunds that boiled down to "owners of green cars are trading them in for SUVs in record numbers."

That may be true--and it has since been widely covered and recirculated by many other sites--but the auto-data giant neglected a crucial point that it really ought to know.

That is, plug-in electric cars are purchased for different reasons than hybrids, so the behavior of their owners is likely to vary significantly.

DON'T MISS: Once More: Low Gas Prices Don't Hurt Electric-Car Sales

But the Edmunds article, with a hook to Earth Day no less, was headlined, "Hybrid and Electric Vehicles Struggle to Maintain Owner Loyalty."

(It didn't help that the company's social-media arm followed it up with a snarky tweet: "What #EarthDay? People are trading in their hybrids/EVs for an SUV in record numbers".)

2015 Cadillac Escalade, 2013 Los Angeles Auto Show

2015 Cadillac Escalade, 2013 Los Angeles Auto Show

The problem with Edmunds' data was aptly summarized by Tom Saxton, chief science officer with Plug In America: "Edmunds' study includes no data about the trade-in rate for plug-in electric vehicles."

In other words, it's possible that trade-in rates for hybrid cars differ from those for plug-in electric cars, and perhaps substantially.

ALSO SEE: Who Buys Plug-In Electric Cars, And Why? CA Report Explains It All For You

Moreover, given that there are several million hybrids on U.S. roads and, thus far, roughly 300,000 electric cars, trade-ins byhybrid owners is likely to swamp any differences in plug-in owner behavior.

Many of the articles that re-reported the study weren't nearly as careful as Edmunds in their headlines.

Gas prices, San Francisco, CA

Gas prices, San Francisco, CA

Pieces by The Verge and Money, among others, not only cited the conflated data but said outright that electric cars are being traded in for SUVs.

That makes for a grabbier headline, but of course it's not supported by the data. Or at least, it won't be until Edmunds provides a breakout.

One difference in the behavior of hybrid buyers vs electric-car buyers is shown by the effect of gas prices. It's well known that hybrid-car sales clearly vary in line with gas prices.

But an analysis by Plug In America of four years of sales data (from December 2010 through November 2014) show absolutely no correlation--zip, nada--between gas prices and the sales of electric cars.

When May data has rolled in, Plug-In America will look at the issue once more--but its analysis late last year was instructive.

U.S. Gasoline Price vs Sales of Plug-In Vehicles, Dec 2010-Nov 2014 [source: Plug-In America]

U.S. Gasoline Price vs Sales of Plug-In Vehicles, Dec 2010-Nov 2014 [source: Plug-In America]

Note in particular the chart above, which shows no correlation between plug-in sales and gas prices).

We hope Edmunds follows up by breaking out its data so that reporters can look at the actual differences between the two sets of owners.

As it stands, the Edmunds article is just like analyzing sales of diesel cars and natural-gas vehicles lumped together because neither uses gasoline.

Or for another analogy, saying that owners are trading in Corvettes for SUVs because Chevy is selling more SUVs.

2015 Nissan Leaf

2015 Nissan Leaf

Neither one is supported by the data provided.

So our memo to reporters would be this: Try to write headlines based on what the data says, rather than what you think someone else said about it after you read it through once, quickly.

Thank you.


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