The Trump tax cuts were justified by a claim that they would pay for themselves because the would stimulate that much growth. It turns out that claim was misleading or an outright lie.

Deficit spending on college education could pay for itself if it was carefully targeted.

Healthcare for workers improves productivity, healthcare and childcare for workers children improves productivity.

Improved productivity does not mean this spending pays for itself, not much of the productivity improvements flow back to the Treasury. It does help offset the inflationary affects of deficit spending as increased productivity has a deflationary affect.

Increased productivity can increase GDP so the debt to GDP ratio does not increase even if the debt increases.

Building infrastructure using debt is OK if the infrastructure reduces costs of production or losses caused by disasters.

TEK