Third, those specialized service firms engaged in the most complex and global- ized markets are subject to agglomeration economies. The complexity ofthe services they need to produce, the uncertainty of the markets they are involved with either directly or through the headquarters for which they are producing the services, and the growing importance of speed in all these transactions, is a mix of conditions that con- stitutes a new agglomeration dynamic. The mix of firms, talents, and expertise from a broad range of specialized fields makes a certain type of urban environment function as an information center. Being in a city becomes synonymous with being in an extremely intense and dense information loop.