Property tax systems in many OECD countries favour single-family homes over multi-occupancy dwellings (thus stimulating urban sprawl) or owner-occupied housing over rental accommodation (thus reducing labour mobility). Such tax arrangements coexist w'ith national and city-level policies intended to curb urban sprawl and improve labour market efficiency. National housing strategies tend to stimulate the housing supply, via direct spending to support new housing construction or facilitate access to home ownership, regulatory tools (e.g. to require municipalities to build social housing as in France) or tax incentives (e.g. deductible interest on mortgage in the United States), for example.