Recently, many researchers have pointed out and demonstrated the existence of multi-attribute reference points in brand choice. However, from the perspective of the two-stage choice model, which posits that consideration set formation precedes brand choice, the following questions arise. First, do reference effects exist at the consideration set formation stage as they do at the brand choice stage? Second, do the reference effects at the brand choice stage disappear when consideration set formation is modeled as a stage preceding brand choice? To address these questions, this study proposed a consideration set formation model incorporating reference effects based on price/quality tiers. Empirical analysis using consideration set data and brand choice data collected through computer simulation yielded the following results: reference effects exist at both the brand choice stage and the consideration set formation stage, and they were more significant at the consideration set formation stage than at the brand choice stage. This implies that much of the reference effect observed in existing brand choice models can be explained merely by endogenous consideration sets. This study discusses the implications of these findings.