Maurizio Iacopetta

Nanotechnology and the Emergence of a General Purpose Technology

This article examines how closely nanotechnology resembles a general purpose technology (GPT). Using patented nanotechnology inventions during 1975-2006, we test for characteristics of GPTs identified in the prior literature, and find evidence that nanotechnology shows both “pervasive” adoption and “spawning” of follow-on innovation. Offering a methodological contribution, we employ concentration indexes such as the Gini index and Lorenz curve to construct “knowledge dissemination curves” for different technologies, thereby providing evidence that nanotechnology shares relevant characteristics with other GPTs. Using an entirely new dataset, we use three different definitions of a “nanotechnology patent” and calculate patent generality indexes, finding that nanotechnology patents are significantly more likely to be referenced across technology space than are patents in information technology, another widely-adopted GPT. In another contribution, we suggest that innovative materials may demonstrate the characteristics of a GPT, and provide a historical parallel between the advancement of steel technology in the 19th Century with that of nanotechnology in the present day.

Dissemination of Technology in Market and Planned Economies

The Soviet Union was competing head to head with market economies in the generation of new technologies, not only in traditional industries such as steelmaking, electricity, and machineries, but also in high tech-areas such as synthetic materials and microelectronics. Yet its productivity performance was significantly worse than that of both developing and industrial countries. R&D-based growth models cannot explain this fact, as the Soviet effort in research and education was comparable to that of most advanced countries. I claim that a technology adoption model helps us understand better the Soviet experience. I hypothesize that the Soviet managerial compensation system generated an incentive for the manager to perform only a modest retooling activity out of fear of breaking the production norm that the planner imposed upon the firm.

Dynamic Programming, Maximum Principle and Vintage Capital

We present an application of the Dynamic Programming (DP) and of the Maximum Principle (MP) to solve an optimization over time when the production function is linear in the stock of capital (Ak model). Two views of capital are considered. In one, which is embraced by the great majority of macroeconomic models, capital is homogeneous and depreciates at a constant exogenous rate. In the other view each piece of capital has its own finite productive life cycle (vintage capital). The interpretation of the time patterns of macroaggregates is quite different between the two cases. A technological shock generates an oscillatory movement in the time pattern of per capita output when capital has a vintage structure; conversely an instantaneous adjustment with no transitional dynamics occurs when capital is homogeneous. From a methodological point of view it emerges that the DP approach delivers sharper results than the MP approach (for instance it delivers a closed form solution for the optimal investment strategy) under slacker parameter restrictions. Cross-time and cross-country data on investments, income, and consumption drawn from the Penn World Table version 6.2 are used to evaluate the vintage and standard Ak model.

The Price of Capital in the AK Model

The AK model predicts that the growth rate of income and the investment rate should move in lockstep. Jones (1995) rejected such an empirical regularity, but under the implicit premise that the price of capital is constant. I propose a parsimonious methodology to adjust the investment rate for the variations in the price of capital and use such a methodology to test the AK model using data on fifty countries during the period 1950-2000. Contrary to Jones, I fail to reject the prediction of the model in the majority of the cases, but the frequency of rejections is only marginally affected by the variations in the price of capital.

ASSET DYNAMICS, LIQUIDITY, AND INEQUALITY IN DECENTRALIZED MARKETS: ASSET DYNAMICS, LIQUIDITY

The Kiyotaki and Wright model has exerted a considerable influence on the monetary search literature. We argue that the model also delivers important insights into a broader range of macroeconomic and development issues. The analysis studies how market frictions and the liquidity of assets affect the distribution of income. Experiments illustrate how the economy adjusts to shocks to asset returns and to the matching technology. They also deal with long‐run transition. An experiment interprets the reversal of fortune hypothesis as a situation in which an economy with a low‐return asset takes over a similar economy with a high‐return asset. (JEL C61, C63, E41, E27, D63)

Dynamics of assets liquidity and inequality in economies with decentralized markets

An algorithm for computing Dynamic Nash Equilibria (DNE) in an extended ver- sion of Kiyotaki and Wright (1989) (hereafter KW) is proposed. The algorithm com- putes the equilibrium pro?le of (pure) strategies and the evolution of the distribution of three types of assets across three types of individuals. It has two features that together make it applicable in a wide range of macroeco- nomic experiments: (i) it works for any feasible initial distribution of assets; (ii) it allows for multiple switches of trading strategies along the transitional dynamics. The algorithm is used to study the relationship between liquidity, production, and inequality in income and in welfare, in economies where assets fetch di¤erent returns and agents have heterogeneous skills and preferences. One experiment shows a case of reversal of fortune. An economy endowed with a low-return asset takes over a similar economy endowed with a high-return asset because, in the former economy, a group of agents abandon a rent-seeking trading behavior and increase their income by trading and producing more intensively. A second experiment shows that a reduction of market frictions leads both to higher income and lower inequality. Other experiments evaluate the propagation mechanism of shocks that hit the assets?returns. A key result is that trade and liquidity tend to squeeze income inequality. Keywords :Trading Startegies, Liquidity, Matching,Decentralized Markets JEL :C61, C63, E41, E27, D63

Human Capital Dispersion and Incentives to Innovate

Do policies that alter the allocation of human capital across individuals affect the innovation capacity of an economy? To answer this question, I extend Romers (1990) growth model to allow for individual heterogeneity. I find that the value of an invention rises with equality. If skills and talents are evenly distributed, inventions are more widely adopted in production and users are willing to bid a higher price. Therefore, more equality is associated with a larger share of the population employed in the business of invention. However, inventors of an equal society are not as creative as those of an unequal one. As a result an inverted-U curve relating inequality and the innovation rate emerges, indicating that departures from extreme forms of equality or inequality are growth-enhancing. I discuss evidence that agrees with the main implications of the analysis, namely that the market size and the number of inventors are negatively affected by inequality. Finally, a calibration exercise suggests that in recent decades the U.S. has been in the ascending portion of the inequality-growth curve.