Forbidden gap argument for phase transitions proved by means of chessboard estimates

Chessboard estimates are one of the standard tools for proving phase coexistence in spin systems of physical interest. In this note we show that the method not only produces a point in the phase diagram where more than one Gibbs states coexist, but that it can also be used to rule out the existence of shift-ergodic states that differ significantly from those proved to exist. For models depending on a parameter (say, the temperature), this shows that the values of the conjugate thermodynamic quantity (the energy) inside the "transitional gap" are forbidden in all shift-ergodic Gibbs states. We point out several models where our result provides useful additional information concerning the set of possible thermodynamic equilibria.Comment: 26 page

How Important Are Foreign Shocks in Small Open Economy? The Case of Slovakia

In this paper, we provide evidence on the nature and the relative importance of domestic and foreign shocks in Slovak economy based on block-restriction vector autoregression model in 1999-2007. We document well-functioning monetary transmission mechanism in Slovakia. Subject to various sensitivity checks, we find that contractionary monetary policy shock has a temporary negative effect on the degree of economic activity and price level. We find that using output gap instead of GDP alleviates the price puzzle. In general, prices are driven mainly by foreign factors and the European Central Bank monetary policy shock on Slovak prices is more powerful than that of the National Bank of Slovakia. Slovak central bank interest rate policy seems to follow the ECB’s interest rates. On the other hand, spectacular Slovak economic growth is primarily driven by domestic factors suggesting the positive role of recently undertaken Slovak economic reforms.small open economy, foreign shocks, monetary policy, Slovakia, euro area.

How Important Are Foreign Shocks in Small Open Economy? The Case of Slovakia

In this paper, we provide evidence on the nature and the relative importance of domestic and foreign shocks in Slovak economy based on block-restriction vector autoregression model in 1999-2007. We document well-functioning monetary transmission mechanism in Slovakia. Subject to various sensitivity checks, we find that contractionary monetary policy shock has a temporary negative effect on the degree of economic activity and price level. We find that using output gap instead of GDP alleviates the price puzzle. In general, prices are driven mainly by foreign factors and the European Central Bank monetary policy shock on Slovak prices is more powerful than that of the National Bank of Slovakia. Slovak central bank interest rate policy seems to follow the ECB’s interest rates. On the other hand, spectacular Slovak economic growth is primarily driven by domestic factors suggesting the positive role of recently undertaken Slovak economic reforms.small open economy, foreign shocks, monetary policy, Slovakia, euro area

A proof of the Gibbs-Thomson formula in the droplet formation regime

We study equilibrium droplets in two-phase systems at parameter values corresponding to phase coexistence. Specifically, we give a self-contained microscopic derivation of the Gibbs-Thomson formula for the deviation of the pressure and the density away from their equilibrium values which, according to the interpretation of the classical thermodynamics, appears due to the presence of a curved interface. The general--albeit heuristic--reasoning is corroborated by a rigorous proof in the case of the two-dimensional Ising lattice gas.Comment: LaTeX+times; version to appear in J. Statist. Phy

How to Solve the Price Puzzle? A Meta-Analysis

The short-run increase in prices following an unexpected tightening of monetary policy represents a frequently reported puzzle. Yet the puzzle is easy to explain away when all published models are quantitatively reviewed. We collect and examine about 1,000 point estimates of impulse responses from 70 articles using vector autoregressive models to study monetary transmission in various countries. We find some evidence of publication selection against the price puzzle in the literature, but our results also suggest that the reported puzzle is mostly caused by model misspecifications. Finally, the long-run response of prices to monetary policy shocks depends on the characteristics of the economy.Monetary policy transmission; Price puzzle; Meta-analysis; Publication selection bias

Evaluating Changes in the Monetary Transmission Mechanism in the Czech Republic

We investigate the evolution of the monetary policy transmission mechanism in the Czech Republic over the 1996-2010 period by employing a time-varying parameters Bayesian vector autoregression model with stochastic volatility. We evaluate whether the response of GDP and the price level to exchange rate or interest rate shocks changes over time, with a focus on the period of the recent financial crisis. Furthermore, we augment the estimated system with a lending rate and credit growth to shed light on the relative importance of financial shocks for the macroeconomic environment. Our results suggest that output and prices have become increasingly responsive to monetary policy shocks, probably reflecting financial sector deepening, more persistent monetary policy shocks, and overall economic development associated with disinflation. On the other hand, exchange rate pass-through has weakened somewhat over time, suggesting improved credibility of inflation targeting in the Czech Republic with anchored inflation expectations. We find that credit shocks had a more sizeable impact on output and prices during the period of bank restructuring with difficult access to credit. In general, our results show that financial shocks are less important for the aggregate economy in an environment of a stable financial system.Monetary policy transmission, sign restrictions, time-varying parameters.

How to Solve the Price Puzzle? A Meta-Analysis

The short-run increase in prices following an unexpected tightening of monetary policy represents a frequently reported puzzle. Yet the puzzle is surprisingly easy to explain away when all published models are quantitatively reviewed. We collect about 1,000 point estimates of impulse responses from 70 articles using vector autoregressive models and present a simple method of research synthesis for graphical results. We find some evidence of publication selection against the price puzzle. Our results suggest that the reported impulse responses depend systematically on the study design: when misspecifications are filtered out, the average impulse response shows that prices decrease soon after a tightening. The long-run response of prices to monetary policy shocks depends on the characteristics of the economy.Meta-analysis, monetary policy transmission, price puzzle, publication selection bias.

Partition function zeros at first-order phase transitions: Pirogov-Sinai theory

This paper is a continuation of our previous analysis [BBCKK] of partition functions zeros in models with first-order phase transitions and periodic boundary conditions. Here it is shown that the assumptions under which the results of [BBCKK] were established are satisfied by a large class of lattice models. These models are characterized by two basic properties: The existence of only a finite number of ground states and the availability of an appropriate contour representation. This setting includes, for instance, the Ising, Potts and Blume-Capel models at low temperatures. The combined results of [BBCKK] and the present paper provide complete control of the zeros of the partition function with periodic boundary conditions for all models in the above class.Comment: 46 pages, 2 figs; continuation of math-ph/0304007 and math-ph/0004003, to appear in J. Statist. Phys. (special issue dedicated to Elliott Lieb