For many decades scholars from various disciplines have been intrigued
by the question whether there are unifying principles or models that
have a validity in different disciplines. The building of such
analytical frameworks bridging the gaps between scientific traditions is
a very ambitious task and has not been very successful up till now. In
the past - in a static context - several such principles have been
defined and advocated at the edge of the natural sciences on the one
hand and social sciences (in particular, economics and geography) on the
other hand, mainly based on the paradigm of 'social physics'. Some
important contributions to the integration of the spatial systems
sciences and physics can be found in gravity theory and entropy theory,
which have formed the comer stones of interaction models in space. This
book is about spatial interaction models. It describes the origin, the
history and the correspondence of such models from a 'social physics'
perspective. It is emphasized that such models need a clear behavioural
underpinning as a sine qua non for a valid use in spatial systems
analysis. This view also explains the use of micro-based disaggregate
choice models as a tool for analyzing spatial systems. This is mainly
analyzed in Part A of this book.