This paper proposes a general theory of individual-level heterogeneity in economic voting based on the perspective that the strength of the relationship varies with factors that influence the relevance of the economic evaluation to the vote choice. We posit that the electoral relevance of the economic evaluation increases with the strength of partisanship as well as political sophistication. Given the strong correlation between partisanship and sophistication, this theoretical perspective casts doubt on extant evidence that more sophisticated voters are more likely to hold the incumbent party electorally accountable for macroeconomic performance since this result might be an artifact of failing to control for the economic evaluation being more relevant to the vote choice of stronger partisans. Our statistical investigation of this question finds no significant evidence that sophistication conditions the economic voting relationship once the conditioning effect of partisanship is included in the model. This finding suggests that individual-level heterogeneity in the strength of the economic voting relationship is largely due to stronger partisans voting more consistently with their national economic evaluation than to more sophisticated voters being more policy-oriented by holding the incumbent party more electorally accountable for macroeconomic performance.