Add takeup variables for childcare subsidies

[nikhilwoodruff]

For each childcare subsidy, we need the percentage of eligible households that receive the benefit.

[nikhilwoodruff]

Per this government survey, 63% of parents of 0-4 year olds used any formal childcare services.

[nikhilwoodruff]

So I'd suggest we use that as the best takeup rate we have so far.

[MaxGhenis]

Sounds good, it's just a starting point for the reweighting anyway

[nikhilwoodruff]

Yes, but we should still aim to be close before reweighting.

[nikhilwoodruff]

I think we should present these as conditional on one another (nobody claims extended without also claiming universal).

So we need good first guesses for p(benunit would claim universal) and p(benunit would claim extended | benunit claims universal).

From some debugging, I think 85% is a good guess for these.