Mr. Noel Cahill:

I do not know how it is done everywhere. In some situations at which I have looked, they may usually be separate. The Netherlands has a well-established system of land management. It still has substantial social housing but it used to be a very large share of its housing output. The Dutch system contained well-established non-profit housing companies that would have developed social housing and housing for middle income people. I do not know how they are combined everywhere.