However, the group receiving unemployment-related SA benefits substantially overlapped with the group receiving housing costs-related SA benefits, and Cappellari and Jenkins argue that the choice of whether to include HB in the definition of SA benefits is of little practical importance. An additional complication was that there were both contribution-based (social insurance) and means-tested (SA) benefits for unemployed workers. However the majority of individuals receiving social insurance also received SA top-ups as well. Ideally one would like to identify only the individuals and families receiving SA (or SA top-ups to insurance benefits) but this turns out to be impossible in practice.