Another example of an externality that improves outcomes

George the monkey eats his dessert (apples) first, then picks the green peppers out of his salad.

When I am in Tamale, I often share my lunch with the office monkey, George. It seems to me that when I share my food with George, my eating habits improve.

There are two reasons for this. The first is simply related to quantity. I don't like to waste food, so normally I clean my plate even if I am no longer hungry.  When George is around, I give him my leftovers when I get full.

The second reason has to do with externalities. When I buy food for myself, I often get lazy and buy fried street food that is available nearby.  If I share food like this with George, I feel bad for feeding him rubbish.  I used to buy egg pies and give George the egg yolk, which I don't like anyway, before I decided that monkeys should probably watch their cholesterol too. As a result, if I know I will be sharing with George, I am more likely to travel farther to get healthy food I will feel good about sharing with the monkey.

I don't know a lot about the field of behavioral economics, but it seems to me that humans, as social animals, may be psychologically wired to internalize externalities through the feelings of guilt and warmfuzzies/self-righteousness.

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