On the Dynamics of the U.S. Manufacturing Productivity Distribution

In this paper a model of productivity dynamics of manufacturing industries is developed with key features being the absence of optimal decisions and equilibrium coordination, heterogeneity of industries with respect to their innovative ability and cumulativeness of innovations together with the working of spillover effects. From that model the law of motion of the productivity distribution across the industries is derived and nonparametrically estimated using data for U.S. manufacturing industries over the period 1958-96. The conclusion of a substantial role of persistence in the productivity development is sharpened by the application of unit root and stationarity tests for panel data.distribution dynamics, productivity, persistence, panel unit root test

Using the Manufacturing Productivity Distribution to Evaluate Growth Theories

Some multi-sector endogenous growth models make strong predictions about productivity differences across sectors in the form of a distribution or density function. In this paper it is demonstrated that this distribution is left-skewed for a wide range of plausible parameter values. This stands in strong contrast to the right-skewed shape of the respective empirical distribution estimated by kernel methods for a measure of relative productivity for more than 450 four-digit U.S. manufacturing industries during 1958-96. This difference is interpreted as evidence in favor of devoting more emphasis on the effects of structural change on the sectoral level in growth models.multisector growth models, manufacturing productivity distribution, skewness

The Sources of Aggregate Productivity Growth - U.S. Manufacturing Industries, 1958-1996

The sources of aggregate productivity growth are explored using detailed data for four-digit U.S. manufacturing industries during 1958-96 and a decomposition formula which allows to quantify the contribution of structural change. Labor productivity as well as total factor productivity are considered and the aggregation is performed with either value-added or employment shares. It is shown that structural change generally works in favor of industries with increasing productivity. This effect is particularly strong in the years since 1990, in high-tech industries and in durable goods producing industries. The impact of the computer revolution can be clearly identified.aggregate productivity growth, structural change, manufacturing

The Global Trends of Total Factor Productivity. Evidence from the Nonparametric Malmquist Index Approach

In this paper the Malmquist index of total factor productivity is applied to a sample of 87 countries observed over the period 1960-90. This index and the method needed to quantify it, the data envelopment analysis, has substantial advantages as compared to traditional growth accounting. Two of these advantages are that it does not rely on questionable equilibrium assumptions to merge multiple inputs into a single index and that the rate of total factor productivity growth can explicitly be decomposed into a measure of efficiency change and the rate of technological progress. Results are reported both in the form of growth rates and measures of relative productivity levels. In each case related labour productivity measures are calculated and the differences to the total factor productivity measures are analysed. Among the topics covered are the productivity slowdown, the Asian Miracle and the bimodality of the distribution of relative producitivity levels.nonparametric productivity measurement, Malmquist index, growth accounting, productivity levels, distribution dynamics

Productivity Dynamics and Structural Change in the U.S. Manufacturing Sector

The paper investigates structural change among the four-digit (SIC) industries of the U.S. manufacturing sector during 1958-96 within a distribution dynamics framework. Focus is on the transition density of the Markov process that characterizes the value added shares of the industries. This transition density is estimated nonparametrically as well as by maximum likelihood, in which case the functional form of the density is derived from a search theoretic model. The nonparametric and the maximum likelihood fits show striking similarities. The relation of structural change to a relative measure of total factor productivity change is tested by an application of quantile regression and is found to be significantly positive throughout.structural change, productivity, manufacturing, quantile regression

Higher level WZW sectors from free fermions

We introduce a gauge group of internal symmetries of an ambient algebra as a new tool for investigating the superselection structure of WZW theories and the representation theory of the corresponding affine Lie algebras. The relevant ambient algebra arises from the description of these conformal field theories in terms of free fermions. As an illustration we analyze in detail the \son\ WZW theories at level two. In this case there is actually a homomorphism from the representation ring of the gauge group to the WZW fusion ring, even though the level-two observable algebra is smaller than the gauge invariant subalgebra of the field algebra.Comment: LaTeX2e, 30 page

Fractional generalization of the Ginzburg-Landau equation: An unconventional approach to critical phenomena in complex media

Equations built on fractional derivatives prove to be a powerful tool in the description of complex systems when the effects of singularity, fractal supports, and long-range dependence play a role. In this paper, we advocate an application of the fractional derivative formalism to a fairly general class of critical phenomena when the organization of the system near the phase transition point is influenced by a competing nonlocal ordering. Fractional modifications of the free energy functional at criticality and of the widely known Ginzburg-Landau equation central to the classical Landau theory of second-type phase transitions are discussed in some detail. An implication of the fractional Ginzburg-Landau equation is a renormalization of the transition temperature owing to the nonlocality present.Comment: 10 pages, improved content, submitted for publication to Phys. Lett.

Higher-Dimensional Integrable Systems from Multilinear Evolution Equations

A multilinear M-dimensional generalization of Lax pairs is introduced and its explicit form is given for the recently discovered class of time-harmonic, integrable, hypersurface motions.Comment: 5 page