Poland's continuing housing shortage reduces labor mobility, which reduces potential growth. Improving housing is essential to improving economic growth in Poland.In this exploration of urban and regional dynamics in Poland after the transition, Deichmann and Henderson find that the degree of urbanization and primacy remains low in Poland. The largest cities are not growing at the rate that would be expected if post-transition adjustments were operating freely. As a result, Poland is not fully realizing external economies from urban agglomeration.Internal migration decreased significantly in the 1990s, with rural-to-urban migration declining dramatically. Current population levels everywhere seem frozen at a degree of urbanization that is low by international standards. Migration levels do not respond to unemployment differentials, perhaps because Poland's continuing housing shortage deters migration. Housing construction, which was already low, fell by half in the 1990s and has only recently begun a slight recovery.A significant number of mostly young and educated temporary migrants leave Poland annually, many to find employment abroad. This may reduce pressure on the Polish labor market but also keeps dynamic actors out of the domestic labor force, reducing growth in urban businesses and industry. Employment in manufacturing and agriculture is relatively concentrated, but specialization seems to have declined in recent years, perhaps reflecting barriers to labor mobility - which could limit growth.That employment in the manufacturing sector is quite concentrated is to be expected in a formerly planned economy. But employment in the service sector is also quite concentrated. A geographic divergence of service activities is not explained by dominant growth in specialized financial and business services in the capital alone. Poland's policymakers should find a way to provide housing, thereby reducing barriers to labor mobility and growth.This paper - a joint product of Infrastructure and Environment, Development Research Group, and the Infrastructure Sector Unit, Europe and Central Asia Region - is part of a larger effort in the Bank to analyze the role of economic geography and urbanization in the development process, particularly as influenced by infrastructure investment and political decentralization. The authors may be contacted at [email protected] or [email protected].