Exports have long been assumed by many to be the most important variable in driving regional growth, although factors such as government expenditure, investment demand, and remittances, among others, have also been recognized as significant. In addition, supply‐side constraints to the promotion of regional growth and development have recently received increased attention in the literature. This paper evaluates the relative importance of exports, investment demand, and remittances, as well as supply‐constrained agricultural production, in determining levels of regional output, value added, and household income in a single region in Kenya. The analysis is based on a mixed endogenous/ exogenous model derived from a social accounting matrix (SAM) which allows for incorporation of both demand and supply‐side considerations. The paper finds that exports are, in fact, the most important factor in explaining regional output and wage income in the region studied, although not overwhelmingly so. In addition, the analysis demonstrates the importance of supply‐constrained agricultural production as a determinant of income at the househol