Are Patent Laws Harmful to Developing Countries? Evidence from China

Has upgrading and enforcing its patent laws slowed China’s economic growth? The answer we draw from detailed analysis of provincial aggregate data covering roughly the period 1990 through 2007 is strongly negative, but understanding the channels through which stricter protection of intellectual property rights has contributed to more rapid productivity growth is elusive. Our best estimate of the direct impact of the 1992 and 2001 patent laws on TFP growth amounts to not quite 15 percent of the average TFP growth rate over the period, but a much larger share of TFP growth is associated with enactment of the laws in a simple interpretation of our empirical investigation. We estimate that virtually none of the laws’ impact on TFP growth can be directly associated with increased quantity of FDI or R&D, although both series are strongly positively correlated with promulgation of the patent laws. We infer that amount of technology transfer through a FDI and the focus of R&D activity, decline of state ownership and increased marketization, growth of the human capital stock, and movement of the labor force from agriculture to manufacturing and service industries are all processes that were encouraged and whose effect has been magnified by stronger IPR protection. Moreover, adopting and enforcing the patent laws probably cannot be treated as an independent event with causation running in only one direction to China’s economic development..Patent law, Intellectual Property Rights, TRIPS, TFP Growth

Quantum Langevin approach for non-Markovian quantum dynamics of the spin-boson model

One long-standing difficult problem in quantum dissipative dynamics is to solve the spin-boson model in a non-Markovian regime where a tractable systematic master equation does not exist. The spin-boson model is particularly important due to its crucial applications in quantum noise control and manipulation as well as its central role in developing quantum theories of open systems. Here we solve this important model by developing a non-Markovian quantum Langevin approach. By projecting the quantum Langevin equation onto the coherent states of the bath, we can derivie a set of non-Markovian quantum Bloch equations containing no explicit noise variables. This special feature offers a tremendous advantage over the existing stochastic Schr\"odinger equations in numerical simulations. The physical significance and generality of our approach are briefly discussed.Comment: 8 pages, 1 figur

Influence of Potamogeton crispus growth on nutrients in the sediment and water of Lake Tangxunhu

An incubation experiment was performed on Potamogeton crispus (P. crispus) using sediment collected from Lake Tangxunhu in the center of China, in order to determine the effects of plant growth on Fe, Si, Cu, Zn, Mn, Mg, P, and Ca concentrations in the sediments and overlying waters. After 3 months of incubation, Ca, Mg, and Si concentrations in the water column were significantly lower, and P and Cu concentrations were significantly higher than in unplanted controls. The effect of P. crispus growth on sediment pore waters and water-extractable elements varied. Concentrations of Ca, Mg, Si, Fe, Cu, and Zn were significantly higher, and P was significantly lower, than in pore waters of the control. Water-extracted concentrations of Fe, Mg, and Si in the sediments were lower, and P was higher, than in the control. Presence of P. crispus generally enhanced concentration gradients of elements between pore waters and overlying waters but not for P. The growth of P. crispus was associated with an increase in water pH and formation of root plaques, resulting in complex effects on the sediment nutritional status