Our Editor asked me to comment on McArdle's post of the above title. Happiness is, as I have discussed here in the past, undefineable.
Joy is defineable, peace of mind is, contentment is, delight is. Pursuit of happiness is a fool's errand. (Is it true that Jefferson's first draft was "pursuit of property", but that was edited out?)
Key quote from her post:
Instead of asking parents and non-parents whether they are happy right now, we might ask whether they are becoming more like the people they want to be. And then we might see children not as factors that may or may not be contributing to our happiness, but as opportunities to practice what most of us -- perhaps me most of all -- need to do more often, which is to put someone else before ourselves.