Neslihan Aydogan It is now widely accepted that geographical proximity
matters to economic and - cial life. Not only does it provide
externalities that reduce transaction costs, but it also helps
transacting parties form networks from which they can bene t greatly.
More than ever, economists have been trying to bridge the development
gap between poor and rich regions. Agglomerations are investigated
toward that target because economists think that if certain regions can
mix up that special formula to conti- ously innovate and produce, then
understanding and forming such agglomerations could be one way to go
about that growth path. We have designed the chapters of this book to
work out the mechanics of geographical agglomerations in the United
States with the focus of identifying the characteristics of such special
formula Chapters 1-3 are designed to investigate the high-tech clusters
that have sprung up in the United States due to their innovative
capacity to engage in high-val- added activities. The rst question we
ask is, What promotes the productivity of high-tech rms? We ask this
question by taking into account the region in which a rm is located and
the spillover effects of the region on the rm. In particular, we ask if
the presence of a variety of industries or of similar industries
promotes the productivity of high-tech rms. In this regard, we are
interested in distingui- ing the high- and low-tech rms in terms of
their driving factors.