A polycarbonate copolymer having repeating units of formula (1), the copolymerization ratio represented by Ar2/(Ar1+Ar2) being 30-47 mol%. Ar1 is a group represented by formula (2a) or (2b), and Ar2 is a group represented by formula (3). The variable n, which is the mean number of repetitions, is 1.12 to 2.34.
