The problem with "just" asking people is that people aren't always aware of the reasons for their own behavior, and even if they are, they are prone to giving socially desirable answers, _especially_ in a social setting like a family Thanksgiving dinner.

Point 1 about affordability is directly contradicted by the fact that low income households are having the most children (except for a tiny minority of ultra rich), and those kids are rarely starving to death.

Point 2 is true, and probably a factor, but even married couples and partners sharing a household are having less children than before.

Point 3 is another excuse: fertility rates are low in _all_ industrialized nations in the world, from Canada, Italy, to Australia, to Japan, with perhaps Israel as the only exception. Meanwhile the countries with high fertility rates are absolutely terrible places to live like Afghanistan or Somalia.