During the Biden years, tax policy related to the family revolved around the child tax credit (CTC). Attempts to expand the credit to make it easier for two-parent families to have kids and rely on a sole breadwinner were thwarted by objections that a child allowance would also promote single-parent families in which no one worked. Policymakers seeking to use the tax code to help strengthen poor and working-class families should shift their focus to the Earned Income Tax Credit (EITC).

The EITC is a refundable tax credit for low earners. Research indicates that the EITC has successfully promoted work over receipt of means-tested benefits. However, because the credit phases out with additional family income, it tends to go to single parents who then stand to lose the credit in the event they marry another worker. The EITC therefore encourages single parenthood.

The US has made great progress reducing child poverty over recent decades. One reason for that success is that welfare reform in the 1990s made it more difficult to rely on federal safety net benefits without working (while an expanded EITC made it more appealing to choose work over welfare). However, reviving the two-parent family was another explicit goal of welfare reform. While the nation has made some limited progress toward this goal—primarily having to do with decades-long worrisome trends leveling out—the share of children growing up with a parent absent from the home remains historically high, and high relative to our peer countries.

I recently proposed a reform to the EITC that would promote marriage and make it easier for working-class married couples to rely on a single earner. If EITC eligibility and benefits were tied to individual earnings, rather than family income, then getting married would not result in loss of income. Moreover, if two parents, each with their own kids, married, they could each use the married-parent EITC schedule for the combined number of kids they have, while as single parents, they could only use the less generous single-parent schedules applicable only to their own dependents. In contrast to current policy, with its marriage penalty, the reformed EITC would actually provide a sizable marriage bonus.

For example, two single parents with one child each would each receive a maximum of around $4,300 in 2025, but if they married they would both qualify for a maximum of over $7,100 (using the schedule for two children), or $14,200 instead of the combined $8,600 they’d get as single parents. Alternatively, they might choose to have a parent at home fulltime, in which case they’d still receive $7,100, reducing the cost of the married sole-breadwinner model by $1,500 relative to current policy. The EITC would be transformed into a program primarily helping low-income single parents to one also benefitting working-class married couples.

The EITC has played a key role in promoting work and thereby reducing poverty. However, we have a long way to go to reverse the decades-long weakening of the two-parent family. My proposal would cost under $400 billion over 10 years—not chump change, but a small price to pay to shore up the family and expand child opportunity in the process.