You are here

Determinacy in Urban Form: Fixed Investment & Path Dependence in Urban Areas

Christian L. Redfearn
Currently the economics of agglomeration receives a great deal of research atten- tion, focusing on a variety of externalities to explain the evolution of cities. Much of this research is ahistorical, with little attention paid to the cumulative history of investment decisions that are manifested in the urban form that researchers seek to understand. This paper presents evidence that the spatial distribution of employment within the Los Angeles metropolitan area remains broadly unchanged during a re- markably dynamic period in terms of the growth and transformation of its population and employment, as well as other of the fundamental variables of urban models such as transportation and communication costs. Over the twenty-year sample period, the number of employment centers and their share of total employment is quite stable, as is the rank of employment density on a tract-by-tract basis. This stability appears to have its origins in the large ¯xed investment in structures and highways made decades earlier. Where employment concentrations are not situated astride one of the arteries in the current highway network (largely established by 1960), their location can be attributed to the freeway system as it stood prior to WWII. Indeed, the spatial distri- bution of current employment centers appears to be explained in no small part by a path dependence that links these centers within the metropolitan area to their distinct antecedents at the turn of the last century