The Effect of Market Entry on Innovation: Evidence from UK University Incubators

This paper investigates the effect of market entry of new firms on incumbent firms' innovative activity measured as patent applications. The basic assumption is that the effect of entry varies by geographical distance between entrants and incumbents due to the presence of localized unobserved spillovers. In order to avoid endogeneity problems commonly associated with the timing of entry and entrants' location choice, I analyze entry induced by the establishment of university business incubators, which are usefully exogenous in time and space. The results show that entry has a statistically and economically significantly positive strategic effect on incumbent patenting which is attenuated by the geographical distance between entrant and incumbent.Patents, market entry, incubators, spillover

Second Order Approximations for Slightly Trimmed Sums

We investigate the second order asymptotic behavior of trimmed sums T_n=\frac 1n \sum_{i=\kn+1}^{n-\mn}\xin, where \kn, \mn are sequences of integers, 0\le \kn < n-\mn \le n, such that \min(\kn, \mn) \to \infty, as \nty, the \xin's denote the order statistics corresponding to a sample $X_1,...,X_n$ of $n$ i.i.d. random variables. In particular, we focus on the case of slightly trimmed sums with vanishing trimming percentages, i.e. we assume that \max(\kn,\mn)/n\to 0, as \nty, and heavy tailed distribution $F$, i.e. the common distribution of the observations $F$ is supposed to have an infinite variance. We derive optimal bounds of Berry -- Esseen type of the order $O\bigl(r_n^{-1/2}\bigr)$, r_n=\min(\kn,\mn), for the normal approximation to $T_n$ and, in addition, establish one-term expansions of the Edgeworth type for slightly trimmed sums and their studentized versions. Our results supplement previous work on first order approximations for slightly trimmed sums by Csorgo, Haeusler and Mason (1988) and on second order approximations for (Studentized) trimmed sums with fixed trimming percentages by Gribkova and Helmers (2006, 2007).Comment: 37 pages, to appear in Theory Probab. App

What Every CCA Should Know About Drainage

Within the cornbelt of the U.S. the use of subsurface drainage systems has been important and perhaps essential in the development of the current agricultural production systems. How water is managed relative to subsurface drainage not only impacts crop production but can also impact the quality and quantity of the water leaving the agricultural field. As a result it is important to understand how subsurface drainage implementation, design, and management may impact crop production and water. This paper and presentation will discuss how subsurface drainage works, how drainage design relative to drain sizing and spacing may impact crop production, and how new technologies for managing drainage water may provide both production and water quality benefits. In addition, some of the commonly held myths about subsurface drainage will be discussed

Export Subsidies in a Heterogeneous Firms Framework: Evidence from Colombia

We evaluate the impact of firm-specific export subsidies on exports in Colombia. Using a twostage selection correction procedure, we obtain firm-specific predicted subsidy amounts that can be explained by the characteristics that determine the firms’ eligibility for government support and its amount. Drawing on the accounts of the discretionary allocation of subsidies in developing countries, we regard the discrepancy between the predicted and the observed subsidy amounts as a proxy for a firm’s ties to government officials. Controlling for observable and unobservable firm characteristics and persistence in exports, we find that although, in general, subsidies exhibit a positive impact on export volumes, this impact is diminishing in subsidy size and in the degree of a firm’s connectedness.Export promotion; export subsidies

INTERTEMPORAL AND INTERSPATIAL VARIABILITY OF CLIMATE CHANGE ON DRYLAND WINTER WHEAT YIELD TRENDS

The importance of climate (temperature and precipitation) variability on Nebraska dryland winter wheat yield trend is examined. The use of short term (1956-1999) climatic divisional panel data (interspatial) and long term (1909-1999) state time series data (intertemporal) is to address the predictability power of estimating the yield trends accounting for climate variability.Resource /Energy Economics and Policy,