Montesino Castro, M.S. and Serrano Alfaro, D.A. 2025. Theory and model of the proportionality of productive forces applied to the coverage of human labor force through fiscal policy and private investment: the case of El Salvador. Investigaciones UCA. 3, 3 (Nov. 2025), 18–22. DOI:https://doi.org/10.51378/iuca.v3i3.10278.