حقوق مالکیت معنوی، پیشرفت فنی و نوسانات رشد اقتصادی

In this note, we analyze the effects of intellectual property rights on the volatility of economic growth. Our analysis is motivated by the observation that the strengthening of patent protection and the increase in R&D in the US coincide with a reduction in growth volatility beginning in the mid 1980s. To analyze this phenomenon, we develop an R&D-based growth model with aggregate uncertainty in the innovation process and apply the model to ask whether increasing patent strength and R&D can lead to a significant reduction in growth volatility. We find a small but non-negligible effect that explains no less than 10% of the observed reduction in growth volatility in the US.

In the early 1980s, the strength of patent rights gradually increased in the US. For example, the Ginarte–Park index of patent rights increased from 3.83 in 1975 to 4.88 in 1995.1 After this patent reform, private R&D expenditure as a percentage of gross domestic product (GDP) in the US increased from 1.2% in 1980 to an average of 2.5% in recent time. Cross-country empirical studies, such as Varsakelis, 2001 and Kanwar and Evenson, 2003 and Park (2005), employ the Ginarte–Park index to examine the effects of patent strength on R&D and innovation, and they generally find a positive and significant effect.2 As for the effects of technical progress on the volatility of economic growth, empirical studies, such as Tang (2002) and Tang et al. (2008), generally find a negative effect; in other words, technical progress reduces growth volatility. In this note, we analyze the effects of patent policy on the volatility of economic growth through technical progress. Our analysis is motivated by the observation that the strengthening of patent rights and the increase in R&D in the US coincide with a reduction in growth volatility beginning in the mid 1980s. To explore this issue, we develop an R&D-based growth model with aggregate uncertainty in the innovation process and apply the model to ask whether the strengthening of patent rights and the increase in R&D in the US can lead to a quantitatively significant reduction in growth volatility. Fig. 1 presents the US time series of growth volatility measured by the coefficient of variation of annual growth in real GDP per capita and shows a well-known pattern that volatility of economic growth in the US fell overtime until the recent crisis.3 Specifically, the coefficient of variation decreased from 1.4 in the mid 1980s to 0.78 in 2007. In the numerical analysis, we calibrate the R&D-based growth model to quantify the fraction of this volatility reduction that can be explained by the increase in R&D and the strengthening of patent protection in the US. In summary, we find a small but non-negligible effect that explains no less than 10% of the observed reduction in growth volatility in the US.Our study relates to the theoretical literature on growth and volatility. Greenwood and Jovanovic (1990) and Acemoglu and Zilibotti (1997) analyze the effect of financial development on volatility and find that financial development can reduce aggregate volatility through financial diversification across firms. Koren and Tenreyro, 2007 and Koren and Tenreyro, 2007b) consider technological diversification instead of financial diversification and show that technological progress improves diversification by increasing the number of input varieties that are subject to imperfectly correlated shocks. Leung et al. (2006) show that rent-seeking behaviors can also give rise to a negative effect of technical progress on growth volatility. Taking the negative growth-volatility relationship as a basic premise that is supported by empirical evidence,4 our study relates to this literature by showing that patent policy can be a useful policy instrument for reducing growth volatility. This study also relates to the literature on patent policy and economic growth. In this literature, one branch of studies analyzes the effects of patent length on growth,5 whereas another branch analyzes the growth effects of other patent levers, such as patent breadth, patentability requirement, intellectual appropriability, protection against imitation, and blocking patents.6 Our paper complements these studies by providing a novel growth-theoretic analysis on the effects of patent policy on the volatility of economic growth. The rest of this note is organized as follows. Section 2 describes the model. Section 3 defines the equilibrium. Section 4 analyzes the effects of patent policy on growth volatility. The final section concludes with a discussion of the model.

In this note, we have analyzed the effects of intellectual property rights on technical progress and growth volatility. In summary, strengthening patent protection improves the incentives for R&D and increases technical progress that in turn reduces the volatility of economic growth. Although the model features a reduced-form relationship between technical progress and growth volatility via a positive externality of R&D spillovers, we believe that this simple setup is appropriate for our purpose for two reasons. First, our focus is on the effect of patent policy on growth volatility while taking the negative effect of technical progress on growth volatility as a basic premise that is supported by empirical evidence. Secondly, it is still an on-going debate as to the main channel through which technical progress reduces volatility; therefore, we adopt a reduced-form setup instead of taking a stand on which structural mechanism is empirically the most relevant. In this study, we have considered a stylized model, so that the numerical results should be viewed as illustrative. In reality, whether or not strengthening patent protection reduces growth volatility significantly depends on two channels: (a) patent policy has a significant and positive effect on technical progress, and (b) technical progress has a significant and negative effect on growth volatility. Existing empirical evidence seems to suggest that both of these channels are often present, especially among high-income countries.13