My favorite parts from my Cato Unbound reply to Betsey Stevenson:

2. My own research confirms Betsey’s first key point: Higher-income
and older parents have a smaller happiness deficit.  And she is
correct to claim that these are precisely the parents most likely to
invest heavily in their kids. Nevertheless, we wouldn’t be so quick to
conclude that over-investment is painless. Studies of momentary
happiness do confirm that childcare feels like work–and Betsey is one
of the very few parents I’ve encountered who suggests otherwise.  The
most natural interpretation of Betsey’s finding, then, is that
over-parenting is positively correlated with better finances, better
preparation, better coping skills, and/or other advantages that more
than compensate. My prediction is that parents who combine these
advantages with a less laborious parenting style will have an
especially small happiness deficit – or perhaps even a happiness
surplus.

3. I completely agree with Betsey that happiness is just one aspect
of a good life. But this point actually strengthens my argument. If we
maximize happiness alone, then potential parents who know the science
might say, “Sure, parents are unhappier than they need to be. But until
you show that parents are actually happier than non-parents, I’ll
remain childless.” But if we maximize a weighted average of, say,
happiness and kids, then all you have to do to tilt the scales in favor
of child-bearing is show that kids cost less happiness than you thought.

One common mistake that Betsey doesn’t make: Claiming that the finding that “kids reduce happiness” invalidates my entire project.  As I’ve explained before, the fact that parents are currently unhappier than comparable non-parents is what makes my evidence so relevant.