1. Department of Environment and Planning, Shangqiu Normal University, Shangqiu 476000, China;
2. Center for Yellow River Civilization and Sustainable Development, School of Environment and Planning, Henan University, Kaifeng 475001, China
Abstract Recent literatures on urban growth have been stressing on the role of technological innovation and spillovers in generating economic growth. Due to the shortage of convincing explorations, tradiional empirical approaches, using the economic classification data to measure technological learning, have some limitation and shortcomings in the study on the relationship between the regional setting and urban growth, and cannot explain the concrete course of the knowledge spillover under the differrent environments. Based on the analysis of Jacob's externalities and the general process of technological innovation, this paper, first, finds out that the characteristics of human creativity and the essence of technological innovation are resulted from the effective combination of the existing, previously unrelated resources or technologies, and the key of technological innovation in the micro level is on the issue how knowledge is actually created and exchanged. Then, the paper probes how knowledge is actually created and exchanged by individuals and how technology is combined through human action and creative uses of resources. The paper holds that the reasons why industry diversity is more beneficial to urban growth than economic specialization can be effectively explained by the more opportunities to combine those heterogeneous resources and technologies. Finally, taking Pittsburgh in the United States as an example, this paper analyses the different effects of the industrial specialization and the diversity on urban growth. It is concluded that the economic diversity is not only more favorable to the combination of different unrelated things, but also can offer more necessary and beneficial settings to inspire the entrepreneurship and the greater agglomeration economy. So the economic diversity other than the industry specialization is more helpful for a city to approach its technological innovation and long-term growth, and the role of industry specialization for urban growth should not be overvalued.
2009, Vol. 24 
