They concluded that the presence of a science park appeared to have had no effect on the rate of growth of high-technology industry in the surrounding city. Both high-tech employment and science parks tend to be associated with urban size: parks are demand-led and emerge in cities that are predisposed to receiving high-technology industry. Thus parks may have been successful due to the presence of demand for space from existing high-technology development, or have quietly failed due to the lack of demand.