The assumption of separability between farm-household production and consumption facilitates analysis, but entails several important restrictions. The implications of assuming separability are discussed here in relation to the modelling of a representative Tongan farm-household. Econometric estimation of household demand is coupled with a linear programming (LP) model of farm-household production. When analysing consumer demand, separable farm-household economics is undoubtedly preferable to ignoring the production/ consumption linkages entirely. However, the restrictions which must be imposed on the production side of the separable model are such that a realistic LP solution is unlikely to be obtained. This is likely to be a major deterrent to adopting the separable approach for studies in which the main focus is on production rather than consumption.