but here ya go ya lazy cunt.
AG abstract: to a point, targeted deficit spending affects economic benefit; the Keynesian standbys of increasing aggregate demand and neo-Keynesian thoughts on spending in a manner where the ROI (id est not digging holes, but spending dollars on young childrens's health and education which sees an exponential economic return by way of the improved economic activity / life outcomes of those children become adults, or infrastructure repair facilitating commerce) but when debt becomes unsustainable you see an increasing proportion of private investment siphoned off to sustain said deficits, resulting in depressed domestic investment in the private sphere, and you see an increasing drag on government finances by way of the proportion of revenue needed to service the interest on the debt. both phenomena ultimately result in less long-term growth and worse long-term economic prospects.
https://www.cbo.gov/sites/default/fi...rkingPaper.pdf
https://www.ecb.europa.eu/pub/pdf/scpwps/ecbwp1237.pdf
https://www.bis.org/publ/othp16.pdf
sources of our own CBO, the EU Central Bank, and the Bank for International Settlements. there is other fair coming from academia if you need but these three provide solid enough primers with emphasis on two of the three advanced economic loci in the world.