Practically, yes - it's more-or-less equivalent. Psychologically, I'm not so sure. Loss aversion is a much stronger than not getting a benefit (think about not

Practically, yes - it's more-or-less equivalent. Psychologically, I'm not so sure. Loss aversion is a much stronger than not getting a benefit (think about not getting your bonus versus taking a pay-cut at work; even if the amounts are the same, I doubt you would feel the same about it) - so I think the explicit tax on childlessness would be more influential because of that.