Parameterized complexity of multiwinner determination: more effort towards fixed-parameter tractability

Abstract We study the parameterized complexity of winner determination problems for three prevalent k -committee selection rules, namely minimax approval voting (MAV), proportional (PAV), and Chamberlin–Courant’s (CCAV). It is known that these are computationally hard. Although they have been studied from point view with respect to several natural parameters, many them turned out be -hard or -hard. Aiming at obtaining plentiful fixed-parameter algorithms, we revisit by considering more single combined structural parameters.