County-level location patterns of INC5000 companies provide one map of American entrepreneurship and innovativeness, and understanding the local factors associated with these firms' emergence is important for stimulating regional economic growth and innovation. We draw on the knowledge spillover theory of entrepreneurship to motivate our regression model, and augment this theory with additional regional features that have been found to be important in the firm-location literature. Zero-inflated negative binomial regressions indicate that these firms exist in counties with larger average establishment size, higher educational attainment, and more natural amenities. Income growth, a mix of higher-paying industries, and more banks per capita are associated with a smaller presence of these types of firms, all else equal. We conclude that the local conditions favoring high growth firms are likely to be different from those favoring new firms in general, and that these conditions differ significantly in urban and rural areas and by industrial sectors.

No abstract

We report on the transition between two regimes from several-atom clusters to much larger nanoparticles in Ar magnetron sputter deposition of WSi2, and the effect of nanoparticles on the properties of amorphous thin films and multilayers. Sputter deposition of thin films is monitored by in situ x-ray scattering, including x-ray reflectivity and grazing incidence small angle x-ray scattering. The results show an abrupt transition at an Ar background pressure Pc; the transition is associated with the threshold for energetic particle thermalization, which is known to scale as the product of the Ar pressure and the working distance between the magnetron source and the substrate surface. Below Pc smooth films are produced, while above Pc roughness increases abruptly, consistent with a model in which particles aggregate in the deposition flux before reaching the growth surface. The results from WSi2 films are correlated with in situ measurement of stress in WSi2/Si multilayers, which exhibits a corresponding transition from compressive to tensile stress at Pc. The tensile stress is attributed to coalescence of nanoparticles and the elimination of nano-voids.

Farmers in China and many other developing countries suffer from low technical efficiency of chemical fertilizer use, which leads to excessive nutrient runoff and other environmental problems. A major cause of the low efficiency is lack of science-based information and recommendations for nutrient application. In response, the Chinese government launched an ambitious nationwide program called the “Soil Testing and Fertilizer Recommendation Project” (STFRP) in 2005 to increase the efficiency of chemical fertilizer use. However, there has been no systematic evaluation of this program. Using data from a nationally representative household survey, and using wheat as an example, this paper first quantifies the technical efficiency of chemical fertilizer use (TEFU) by conducting stochastic frontier analysis (SFA), then evaluates the impact of STFRP on the TEFU using a generalized difference-in-difference approach. We found that STFRP, on average, increased TEFU in wheat production by about 4%, which was robust across various robustness checks. The lessons learned from STFRP will be valuable for China’s future outreach efforts, as well as for other countries considering similar nutrient management policies.

No abstract