Another I just thought of was Obama's "cash for clunkers" plan that scrapped hundreds of thousands of used cars for environmental reasons.

It created a temporary boost of new-car in the initial months, followed by a slump. But ultimately, it didn't change anyone's decision to make them buy a new car, it just sped up the decision to buy by those already predisposed to do so.

And for years after, it created an artificial scarcity of used cars, that just made it far more expensive for several years to buy a used car. Another manifestation of the economic genius of Comrade Obama and his Central Committee.