A Model of TFP

This paper proposes an aggregative model of Total Factor Productivity (TFP) in the spirit of Houthakker (1955-1956). It considers a frictional labor market where production units are subject to idiosyncratic shocks and jobs are created and destroyed as in Mortensen and Pissarides (1994). An aggregate production function is derived by aggregating across production units in equilibrium. The level of TFP is explicitly shown to depend on the underlying distribution of shocks as well as on all the characteristics of the labor market as summarize by the job-destruction decision. The model is also used to study the effects of labor-market policies on the level of measured TFP.

A two band model for Superconductivity: Probing interband pair formation

We propose a two band model for superconductivity. It turns out that the simplest nontrivial case considers solely interband scattering, and both bands can be modeled as symmetric (around the Fermi level) and flat, thus each band is completely characterized by its half-band width $W_{n}$ (n=1,2). A useful dimensionless parameter is $\delta$, proportional to $W_{2}-W_{1}$. The case $\delta =0$ retrieves the conventional BCS model. We probe the specific heat, the ratio gap over critical temperature, the thermodynamic critical field and tunneling conductance as functions of $\delta$ and temperature (from zero to $T_{c}$). We compare our results with experimental results for $MgB_{2}$ and good quantitative agreement is obtained, indicating the relevance of interband coupling. Work in progress also considers the inclusion of band hybridization and general interband as well as intra-band scattering mechanisms.Comment: 7 pages, 5 figures (in postscript format). PACS numbers: 74.20.-z, 74.20.Fg, 74.70.A

Promoting an Effective Market Economy in a Changing World

In this paper we examine the main challenges in promoting an effective market economy. While the paper ranges widely across the spectrum of economic institutions and policies, the central theme is the importance of macroeconomic stability for economic growth in the medium and long run. Macroeconomic stability may be seen as a public good. Its provision is among the essential responsibilities of the state both in modern market economies and in economies transforming themselves into modern market economies. Following this brief introduction, Section II considers four key aspects of the economic environment of the coming decade: increasing internationalisation; market-orientation; diminished government role; high real interest rates. Section III reviews the reasons why macroeconomic stability matters for economic performance and summarises the key empirical evidence supporting the existence of a causal link. Section IV deals with the design of domestic and international policies and institutions to promote macroeconomic stability and Section V asks how national governments and international institutions can take advantage of the current relatively stable global macroeconomic environment to improve medium-term growth. Section IV concludes. While our discussion will range broadly both theoretically and empirically, we shall emphasise lessons for , and experience from, countries attempting to create a market economy.

Enterprises in Transition: Macroeconomic Influences on Enterprise Decision-Making and Performance

This paper analyses the theoretical arguments and empirical evidence linking enterprise performance in transition economies to the macroeconomic environment. Macroeconomic instability is traced to the unsustainability of the fiscal-financial and monetary programmes of the state and to regulatory and other failures leading to problems with the solvency of financial institutions. The importance of macroeconomic stability for enterprise performance is documented with a simulation study and by reviewing relevant microeconomic and aggregate empirical evidence from across the world, as well as from the transition economies themselves. Conclusions are reached about the speed of transition, about the synergy between macroeconomic stabilisation and market development and about the creation of institutions for achieving and maintaining macroeconomic stability.

Present and potential land use mapping in Mexico

The Mexican Water Plan (MWP) conducted studies of present and potential land use in Mexico using LANDSAT-1 satellite imagery. Present land use studies were carried out all over the country (197 million hectares); nine soil uses were mapped according to the first classification level recommended by the U.S. Geological Survey. Also 6.3 million hectares of land with advanced erosion were detected. Work was executed at a rate of 8 million hectares per month; reliability was 90% and the cost of only 0.1 cents/hectare. The potential land use study was performed in 45 million hectares at a rate of 4 million hectares per month and at a cost of 0.33 cents/hectare. Soil units according to FAO classification were delineated scale 1:1 million; interpretative maps were also prepared dealing with potential agricultural productivity carrying capacity for cattle, water, erosion risk, and slope ranges

Big Data on Decision Making in Energetic Management of Copper Mining

Indexado en: Web of Science; Scopus.It is proposed an analysis of the related variables with the energetic consumption in the process of concentrate of copper; specifically ball mills and SAG. The methodology considers the analysis of great volumes of data, which allows to identify the variables of interest (tonnage, temperature and power) to reach to an improvement plan in the energetic efficiency. The correct processing of the great volumen of data, previous imputation to the null data, not informed and out of range, coming from the milling process of copper, a decision support systems integrated, it allows to obtain clear and on line information for the decision making. As results it is establish that exist correlation between the energetic consumption of the Ball and SAG Mills, regarding the East, West temperature and winding. Nevertheless, it is not observed correlation between the energetic consumption of the Ball Mills and the SAG Mills, regarding to the tonnages of feed of SAG Mill. In consequence, From the experimental design, a similarity of behavior between two groups of different mills was determined in lines process. In addition, it was determined that there is a difference in energy consumption between the mills of the same group. This approach modifies the method presented in [1].(a)http://www.univagora.ro/jour/index.php/ijccc/article/view/2784/106