In the US, you have different tax status if you're married. There used to be a marriage "penalty" for dual income households because of progressive buckets (the

In the US, you have different tax status if you're married. There used to be a marriage "penalty" for dual income households because of progressive buckets (the combined income would push you into higher marginal rates). i.e. it would actually make sense to not officially get married for tax purposes. Trump mostly eliminated that, and now everything but the top marginal rate (above ~600k) has doubled thresholds when married. However merely using progressive rates isn't enough; people see it as a penalty for getting married, not having a dual income. You'd want something like a credit for stay-at-home childcare to directly incentivize it. Right now, we actually subsidize working parents through childcare tax credits/deductions. We could at least make this more neutral by eliminating childcare incentives and increasing the child tax credit.