12,811 research outputs found

### Spatial effects on the aggregate demand

This paper analyses if several spatial variables coming from cities and transportation system can affect the money market, specially the income velocity of circulation. The specification of the theoretical model include the income velocity of circulation into the IS-LM multipliers. Considering the Baumol-Tobin model for transaction money demand, the Central Place Theory, and some gravity models, we can conclude that the incom velocity of circulation and the supply money in monetary terms are dependent, among others, of seven spatial variables such as the country first city population, the population density, the passenger-kilometers transported by railways, and several ratios referred to some geographical variables. The model has been applied across 64 countries during the period 1978-1997. Panel data techniques has been used for estimating the model. Thresults indicate that most of the explanatory variables are significant on income velocity of circulation and the money supply. The macroeconomic equilibriunm is affected by the spatial explanatory variables because these last affect the LM curve, an hence prices and output level maybe influenced because of that.

### Spatial Effects on the Aggregate Demand

The main aim of this paper is to analyse if determined variables related with transportation, demography and geography can cause fluctuations in the aggregate demand function and hence affect the prices,employment and output levels in an economy.The panel data to carry out this analysis includes 64 countries (19 european, 14 african, 17 asian, 14 american) during 21 years (1978-98).The specification of the model is based in to relate the Baumol-Tobin model for demand money transaction, with the central places theory for obtaining a relationship between money velocity and variables such as population density, passenger-kilometers and net tons-kilometers transported by railway, the first city population, and several ratios corresponding with road transportation. Panel data techniques have been aplyed and estimation results indicate that all explanatory variables are significant and all cause Granger on money velocity during this period. Unit roots test of Harris-Tzavalis and cointegration test of Chiwa Kao notify that the relationship between money velocity and this explanatory variables is not spurious and it is a long run relation. But money velocity at long run is a component of the slope of LM curve, and hence fluctuations in the explanatory variables can cause movements in the LM curve and in the aggregate demand function affecting the output level and prices.

### Spatial effects on technical progress: growth, and convergence among countries

This paper analyses how several spatial variables coming from cities and transportation system can affect money market, specially the income velocity of circulation, assuming an unit-elastic aggregate demand function and considering money velocity as a variable. Fluctuations in velocity caused by some spatial variables, under certain conditions, can affect the aggregate demand curve. The specification of the main relation-ship has found in the Baumol-Tobin model for transaction money demand, and in Christaller-LĂ¶sch central place theory. The estimation of the model has been based on panel data techniques and applied across 61 countries during 14 years in the 1978-1991 period. Theoretical and econometric results indicates that seven spatial variables like the countryâ€™s first city population, the population density, the passengers-kilometer transported by railways, and several ratios referred to some geographical variables, can provokes fluctuations on aggregate demand curve in the short run. In the long run, the aggregate supply can be also affected by means of these variables. In order to checking this question, considering that these spatial variables are not product factor, we propose to observe if these variables can affect the technological progress coefficient, A, concerning to an aggregate production function, according to a neo-classical growth model. Results by means of the Mankiw, Romer and Weil method, and also by means of an endogenous growth model of technology diffusion, indicates that some spatial variables affect the speed of convergence relative to the real per head income, across these 61 countries. However, a certain amount in some of these variables generates a congestion process in some countries. For checking it, we utilize a Barro and Sala i Martin endogenous growth model which reflects government activities. The concluding remarks indicates that some of these spatial variables above mentioned increases the speed of convergence but generates congestion in some countries. These spatial variables also affect the aggregate supply, and hence the price and output levels. Key words: transportation, regional growth, convergence, congestion. JEL Class.: R41

### Quality capital and economic growth

The productivity generated by capital goods is not uniform, specially over the time. The productivity obtained from phisical goods is minor than one generated by new capital goods, or quality capital goods. It seems that the difference between both kinds of capital stems from the fact that vintage capital is affected by an additional form of technical progress. When capital is affected by this kind of technical progress, it is so-called capital jelly from Solow (1960). There are hence two possible forms of understand technical progress: the classical one or, alternatively, this new class of technical progress tath affects only to capital. Both kinds of technical progress affect growth in two separate ways, and for this reason it is interesting to develop a special analysis on the investment in capital goods in order to identify what is the difference between the productivity derived from physical capital and from vintage capital. The main aim of this paper is to analyse how two types of technical progress affcet the real income growth rate in the countries belonging to three world areas: North America, the Euro zone, and some countries of the Pacific Rim, during the period 1960-2000. Precursory works of the present research have found in Hulten (1992), Greenwood, Hercowitz and Krusell (1997), Gordon (1999) and Hobijn (2000).

### Particle identification with the AMS-02 RICH detector: search for dark matter with antideuterons

The Alpha Magnetic Spectrometer (AMS), whose final version AMS-02 is to be
installed on the International Space Station (ISS) for at least 3 years, is a
detector designed to measure charged cosmic ray spectra with energies up to the
TeV region and with high energy photon detection capability up to a few hundred
GeV, using state-of-the art particle identification techniques. It is equipped
with several subsystems, one of which is a proximity focusing Ring Imaging
Cherenkov (RICH) detector equipped with a dual radiator (aerogel+NaF), a
lateral conical mirror and a detection plane made of 680 photomultipliers and
light guides, enabling precise measurements of particle electric charge and
velocity (Delta beta / beta ~ 10^-3 and 10^-4 for Z=1 and Z=10-20,
respectively) at kinetic energies of a few GeV/nucleon. Combining velocity
measurements with data on particle rigidity from the AMS-02 Tracker (Delta R /
R ~ 2% for R=1-10 GV) it is possible to obtain a reliable measurement for
particle mass. One of the main topics of the AMS-02 physics program is the
search for indirect signatures of dark matter. Experimental data indicate that
dark, non-baryonic matter of unknown composition is much more abundant than
baryonic matter, accounting for a large fraction of the energy content of the
Universe. Apart from antideuterons produced in cosmic-ray propagation, the
annihilation of dark matter will produce additional antideuteron fluxes.
Detailed Monte Carlo simulations of AMS-02 have been used to evaluate the
detector's performance for mass separation, a key issue for anti-D/anti-p
separation. Results of these studies are presented.Comment: 5 pages. Contribution to the 20th European Cosmic Ray Symposium
(Lisbon 2006). Presenter: Rui Pereir

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