When no Input–Output Table exists, a SAM can still be constructed by relying on national accounts, household surveys, labor force data, and government accounts as the main data sources. Researchers often borrow technology coefficients from similar economies or past IOTs, and then apply balancing techniques such as RAS or cross-entropy methods to ensure consistency. The process usually begins with a macro-SAM and progressively disaggregates into detailed accounts once sufficient information is available.