Labour Productivity Superstatistics

We discuss superstatistics theory of labour productivity. Productivity distribution across workers, firms and industrial sectors are studied empirically and found to obey power-distributions, in sharp contrast to the equilibrium theories of mainstream economics. The Pareto index is found to decrease with the level of aggregation, {\it i.e.}, from workers to firms and to industrial sectors. In order to explain these phenomenological laws, we propose a superstatistics framework, where the role of the fluctuating temperature is played by the fluctuating demand.Comment: 13 pages including figure

"Uncertainty, Policy Ineffectiveness, and Long Stagnation of the Macroeconomy"

The standard analysis in macroeconomics depends on the assumption of the representative agent. However, when the degree of uncertainty becomes significant, we cannot ignore a simple fact that the macroeconomy consists of a large number of heterogeneous agents. In this paper, we demonstrate the importance of the combinatory aspect. Specifically, the effectiveness of policy necessarily weakens as the degree of uncertainty rises. One might call this probrem "uncertainty trap". This may contribute to long stagnation of the macroeconomy.

"Non-Self-Averaging in Macroeconomic Models: A Criticism of Modern Micro-founded Macroeconomics"

Using a simple stochastic growth model, this paper emonstrates that the coefficient of variation of aggregate output or GDP does not necessarily go to zero even if the number of sectors or economic agents goes to infinity. This phenomenon known as non-self-averaging implies that even if the number of economic agents is large, dispersion can remain significant, and, therefore, that we can not legitimately focus on the means of aggregate variables. It, in turn, means that the standard microeconomic foundations based on the representative agent has little value for they are expected to provide us with dynamics of the means of aggregate variables. The paper also shows that non-self-averaging emerges in some representative urn models. It suggests that non-self-averaging is not pathological but quite generic. Thus, contrary to the main stream view, micro-founded macroeconomics such as a dynamic general equilibrium model does not provide solid micro foundations.

"A New Model of Economic Fluctuations and Growth"

This paper presents a model of the dconomy with many sectors which face demand (quantity) constraints. Depending on the sign of the sectoral excess demand, the size of each sector either increases or decreases stochastically. We assume that reallocation of resources is not instantaneous, and, therefore, that sectoral differences in productivity always exist. We rely on the notion of holding time of continuous time Markov chains to select the sector which changes its size. We demonstrate that the total output fluctuates, and more importantly, that the level of the aggregate economic activity depends on the pattern of demand; The greater is demand for high productivity sectors, the higher is the expected value of GDP.

Low Fertility, Aging Population, and Economic Growth (Japanese)

This publication is in Japanese. Neither an English translation of the publication nor an English abstract is available.