More on how we even got the $7500 EV subsidy figure:

“In 2008 the Bush administration was thinking of doing an EV subsidy, so they asked the Government Accountability Office to figure out how much gasoline was subsidized. The answer was $2/gallon; or at average mpg and lifetime miles for vehicles at the time, about $12,000 per car. (Source: http://www.amazon.com/JOLT-Impending-Dominance-Electric-America/dp/159932220X)

Note that that calculation was ONLY for hard petroleum subsidies (though it’s the common definition of subsidy, which includes things like tax credits). It did not includes wars in oil-producing countries, 20k annual deaths in the US from health effects, pollution mitigation, the $85B a year to patrol the Straight of Hormuz, etc.

That $12k was spread over the life of the car, so they figured an equivalent net-present-value amount would be $7,500. That’s why we have that for a tax credit on EVs.”