Behavior often deviates from standard predictions because individuals evaluate the consequences of choices separately (i.e., narrow bracketing) rather than jointly. The main existing theories classify different narrow bracketing phenomena as either (i) choice errors caused by cognitive limitations, or (ii) strategies to achieve self-control. Using an online experiment, we find consistent evidence for theory (ii): mental budgets and narrow goals are related to each other and to measures of self-control, but are distinct from other forms of narrow bracketing. Evidence for the complementary theory (i) is less consistent: few choice bracketing phenomena are related to each other and to cognitive skills.