Dietmar Harhoff

Citation Frequency and the Value of Patented Innovation

Through a survey, private economic value estimates were obtained on 964 inventions made in the United States and Germany and on which German patent renewal fees were paid to full-term expiration in, 1995. A search of subsequent U.S. and German patents yielded counts of citations to those patents. Patents renewed to full-term were significantly more highly cited than patents allowed to expire before their full term. The higher an inventions economic value estimate was, the more the patent was subsequently cited.

Citations, family size, opposition and the value of patent rights

Abstract We combine estimates of the value of patent rights from a survey of patent-holders with a set of indicator variables in order to model the value of patents. Our results suggest that the number of references to the patent literature as well as the citations a patent receives are positively related to its value. References to the non-patent literature are informative about the value of pharmaceutical and chemical patents, but not in other technical fields. Patents which are upheld in opposition and annulment procedures and patents representing large international patent families are particularly valuable.

Profiting from Voluntary Information Spillovers: How Users Benefit by Freely Revealing Their Innovations

Empirical studies of innovation have found that end users frequently develop important product and process innovations. Defying conventional wisdom on the negative effects of uncompensated spillovers, innovative users also often openly reveal their innovations to competing users and to manufacturers. Rival users are thus in a position to reproduce the innovation in-house and benefit from using it, and manufacturers are in a position to refine the innovation and sell it to all users, including competitors of the user revealing its innovation. In this paper we explore the incentives that users might have to freely reveal their proprietary innovations. We then develop a game-theoretic model to explore the effect of these incentives on users’ decisions to reveal or hide their proprietary information. We find that, under realistic parameter constellations, free revealing pays. We conclude by discussing some implications of our findings.

Lending relationships in Germany - Empirical evidence from survey data

We examine empirically the role of lending relationships in determining the costs and collateral requirements for external funds. The data originate from a recently concluded survey of small and medium-sized German firms. In our descriptive analysis, we explore the borrowing patterns and the concentration of borrowing from financial institutions. Using data on L/C interest rates, collateral requirements, and the firms use of fast payment discounts we find that relationship variables may have some bearing on the price of external funds, but much more so on loan collateralization and availability. Firms in financial distress face comparatively high L/C interest rates and reduced credit availability.

Technology policy for a world of skew-distributed outcomes

Abstract This paper draws implications for technology policy from evidence on the size distribution of returns from eight sets of data on inventions and innovations attributable to private sector firms and universities. The distributions are all highly skew; the top 10% of sample members captured from 48 to 93 percent of total sample returns. It follows that programs seeking to advance technology should not be judged negatively if they lead to numerous economic failures; rather, emphasis should be placed on the relatively few big successes. To achieve noteworthy success with appreciable confidence, a sizeable array of projects must often be supported. The outcome distributions are sufficiently skewed that, even with large numbers of projects, it is not possible to diversify away substantial residual variability through portfolio strategies.

Legal Form, Growth and Exit of West German Firms: Empirical Results for Manufacturing, Construction, Trade and Service Industries

Using a sample of approximately 11,000 West German firms from all major sectors of the economy, the authors test predictions on the relationship between legal form, firm survival, and employment growth. In their tests, the authors distinguish between voluntary liquidation without losses to creditors and bankruptcy, that is forced liquidation. They demonstrate that, in all sectors, firms under limited liability have higher growth and higher insolvency rates than comparable firms under full liability. Firms whose owners are approaching retirement age are characterized by relatively high hazards of voluntary liquidation, while the propensity to declare insolvency is not affected by the owners age. Copyright 1998 by Blackwell Publishing Ltd

Are there financing constraints for R&D and investment in German manufacturing firms?

Using a newly constructed panel dataset of German enterprises, I estimate R&D and capital investment equations for the time period from 1990 to 1994. Simple accelerator specifications indicate considerable sensitivity of R&D and investment to cash flow for relatively small firms. Much of this effect vanishes already once error-correcting behavior is taken into account, but a significant positive relationship between cash flow and investment remains for relatively small firms. In the case of R&D, weak but significant cash flow persist both for small and large firms. The evidence from Euler equation estimates is not conclusive. The investment Euler equation for large firms appears to perform relatively well and yields results close to those expected under the null hypothesis of no financing constraints. The estimates from the Euler equation for R&D are not informative. Additional evidence from survey data suggests that the cash flow sensitivity of investment in small firms is likely to reflect financing constraints.

Venture Capitalists' Evaluations of Start-Up Teams: Trade-Offs, Knock-Out Criteria, and the Impact of VC Experience

The start–up team plays a key role in venture capitalists’ evaluations of venture proposals. Our findings go beyond existing research, first by providing a detailed exploration of VCs’ team evaluation criteria, and second by investigating the moderator variable of VC experience. Our results reveal utility trade–offs between team characteristics and thus provide answers to questions such as “What strength does it take to compensate for a weakness in characteristic A?” Moreover, our analysis reveals that novice VCs tend to focus on the qualifications of individual team members, while experienced VCs focus more on team cohesion. Data were obtained in a conjoint experiment with 51 professionals in VC firms and analyzed using discrete choice econometric models.

The Duration of Patent Examination at the European Patent Office

We analyze the duration and outcomes of patent examination at the European Patent Office utilizing an unusually rich data set covering a random sample of 215,265 applications filed between 1982 and 1998. In our empirical analysis, we distinguish between three groups of determinants: applicant characteristics, indicators of patent quality and value, and determinants that affect the complexity of the examination task. The results from an accelerated failure time model indicate that more controversial claims lead to slower grants but faster withdrawals, whereas well-documented applications are approved faster and withdrawn more slowly. We find strong evidence that applicants accelerate grant proceedings for their most valuable patents, but that they also prolong the battle for such patents if a withdrawal or refusal is imminent. This paper develops implications of these results for managerial decision making in research and development and innovation management.

R&D and Productivity in German Manufacturing Firms

This papcr uses a new firm panel data set to explore the relationship between R&D and productivity in German manufacturing firms for the period from 1979 to 1989. The results confirm the view that K&D is an important determinant of productivity growth. In the cross-section, the elasticity of sales with respect to R&D capital is on the order of 14 per cent. Using fixed-effects estimators yields R&D elasticities of about 8 per cent. Assuming different depreciation rates for R&D capital has virtually no effect on these results. Differencing estimates improve considerably when growth rates are computed over longer time periods, suggesting that the divergence between time-series and cross-sectional estimates is driven by random measurement errors. The paper also considers differences between high technology and other firms. Cross-section and panel elasticity estimates of the R&D effect diverge considerably for the two groups, while the corresponding rate of return estimators display far less variation. There is some evidence that the R&D elasticity increased during the early 1980s, and that it fell sharply back to its 1979 value during the period from 1985 to 1989.