Data is important. Data on the effects of changing economic factors is very important to the car industry.
Which is why it's disappointing to see a Nissan executive repeating the canard that falling gas prices can hurt sales of plug-in electric cars.
In an interview, Nissan's North American vice president for product planning, tells trade journal Ward's Auto that, "with (oil at) $47 a barrel, it makes [selling electric cars] even more challenging."
It's a side comment to the main point of the story, but it's regrettable.
2015 Nissan Leaf
The main point of the Ward's story was Loing saying that when Nissan has sold 200,000 electric cars in the U.S., it will be prepared for the end of the $7,500 Federal income-tax credit for purchase of an electric car.
Those credits are limited to 200,000 vehicles delivered by each carmaker, after which they sunset on a short schedule.
But the data thus far show that gas prices appear to have no correlation whatsoever to U.S. sales of plug-in hybrid and battery-electric vehicles.
A blog post last month by electric-car advocacy group Plug-In America mapped gas prices (which fluctuated a lot) against sales of plug-in cars from December 2010 through November 2014, or a full 48 months of data.
U.S. Gasoline Price vs Sales of Plug-In Vehicles, Dec 2010-Nov 2014 [source: Plug-In America]
The group's conclusion?
Data from the period between December 2010 and November 2014 shows zero correlation between gasoline prices and plug-in vehicle sales.
The data does not support the idea that falling gasoline prices have a negative effect on sales of plug-in vehicles.
Plug-in vehicle sales appear to be independent of gasoline prices.
And there you have it.