  Over the last few years, researchers have put significant effort into
understanding of the notion of proportional representation in committee
election. In particular, recently they have proposed the notion of
proportionality degree. We study the complexity of computing committees with a
given proportionality degree and of testing if a given committee provides a
particular one. This way, we complement recent studies that mostly focused on
the notion of (extended) justified representation. We also study the problems
of testing if a cohesive group of a given size exists and of counting such
groups.
