The consistency between purchase intentions and behavior is of critical importance to marketing managers and academics since intention data is in heavy use to represent real purchase behavior in surveys and experiments. Prior research has investigated product-related and individual-related ‘modifiers’ to explain the gap between intention and behavior. However, no research has addressed the difference between category-level and brand-level purchase consistency and explored the differentiating roles of the modifiers. This paper develops a model of desirability-feasibility-change to help understand the modifying mechanism and examines the differentiating effects of four ‘modifiers’ including income, information search, need construal level and preference strength on category-level and brand-level consistency. The results show that income has a negative effect on category consistency but has no effect on brand consistency. Information search has a positive effect on category consistency but has a negative effect on brand consistency. Need construal level has negative effects on both category consistency and brand consistency. Preference strength has a positive effect on brand consistency but has no effect on category consistency.