Note: This is post #38 in a weekly video series on basic microeconomics.

What happened to the cleanliness of your clothes after the U.S. Department of Energy issued new washing machine requirements? The requirements — which require washers to use 21% less energy — mean that washers actually clean clothes less than they used to, says economist Alex Tabarrok. In this video by Marginal Revolution University, Tabarrok considers whether mand and control” is an efficient way to achieve the desired e of less pollution).

(If you find the pace of the videos too slow, I’d mend watching them at 1.5 to 2 times the speed. You can adjust the speed at which the video plays by clicking on “Settings” (the gear symbol) and changing “Speed” from normal to 1.25, 1.5 or 2.)

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