We came close to overturning comparative advantage last night with our new juice-squeezer. Using it requires peeling the oranges, which involves rolling them around, making two circumferential cuts, and then stripping the flesh out. Only then can the flesh be thrown in the squeezer. After doing this together, my wife announced that I was so incompetent that the elapsed time in the first three steps would be less if she did everything and I watched. What she really meant was, "Daniel, your marginal productivity is very low! (But it wasn't negative: I was able to put the oranges in the squeezer, but she could have done that too, and the "assembly line" would have moved faster.)
How many household production activities are there where even the second cook “spoils the broth”?