The Berlin workshop series 2009 presents a selection of papers from meetings held on September 30-October 2, 2007, at the tenth annual Berlin workshop, jointly organized by InWent-Capacity Building International, Germany, and the World Bank in preparation for the World Bank's World Development Report (WDR) 2009. The workshop brings diverse perspectives from outside the World Bank, providing a forum in which to exchange ideas and engage in debate relevant to development of the WDR. The report will accordingly have three parts, each describing, explaining, or drawing lessons from the spatial transformations that have been observed in both developed and developing countries. The first section of the report will be factual and present the stylized facts on economic concentration and welfare disparities, for both developing and developed countries, over the last two centuries. The second part of the report will identify the main drivers of these changes, distilling the insights provided by the advances in economic thought over the last two decades. The third section of the report will discuss the policy implications, in essence identifying the public policy priorities that help countries to realize the immediate economic benefits of greater concentration and the social and long-term economic benefits of moderate spatial disparities. In essence, the report will emphasize that neighborhoods are important for development. This is true for cities, for regions, and for countries: it is difficult for a city to prosper in the middle of a squalid countryside, it is difficult for a province to prosper rapidly when other provinces in the country are squalid, and it is difficult for a country to prosper for long when the countries around it are mired in squalor. The report will propose that the solution for cities, regions, and countries is to invest in neighborhoods. The principle is to deepen integration and not to attempt isolation.