Pancheva (2009) argues that phrasal comparatives in Polish exhibit a subject-island effect. She proposes an account of the island effect as a combination of several factors: than has a small clause complement in phrasal comparatives; wh-movement turns the than-clause into a degree predicate; wh-movement of the vP subject is prohibited by an anti-locality constraint; sub-extraction of the vP subject is then the only option, but it causes an island violation. Informally elicited judgments support this proposal but there is a fair amount of variability among and even within speakers. Given this variability in speakers’ responses, we need to elicit judgments in controlled conditions allowing subsequent quantitative analysis. We conducted two acceptability-rating studies on Polish comparatives following standard experimental procedures and testing a large number of speakers. The results support the small clause analysis of phrasal comparatives.