The use of long-run restrictions for the identification of technology shocks

The authors survey the recent empirical literature using long-run restrictions to identify technology shocks and provide an illustrative walk-through of the long-run restricted vector autoregression (VAR) methodology in a bivariate framework. Additionally, they offer an alternative identification of technology shocks that can be imposed by restrictions on the long-run impulse responses to evaluate the robustness of the conclusions drawn by the structural VAR literature. Their results from this methodology compare favorably with the empirical literature that uses structural VARs to identify technology shocks.Business cycles ; Technology

What explains the varying monetary response to technology shocks in G-7 countries?

In a recent paper, Galí, López-Salido, and Vallés (2003) examined the Federal Reserve’s response to VAR-identified technology shocks. They found that during the Martin-Burns- Miller era, the Fed responded to technology shocks by overstabilizing output, while in the Volcker-Greenspan era, the Fed adopted an inflation-targeting rule. We extend their analysis to countries of the G-7; moreover, we consider the factors that may contribute to differing monetary responses across countries. Specifically, we find a relationship between the volatility of capital investment, type of monetary policy rule, the responsiveness of the rule to output and inflation fluctuations, and the response to technology shocks.Technology ; Monetary policy ; Taylor's rule

What Explains the Varying Monetary Response to Technology Shocks in G-7 Countries?

In a recent paper, Galí, López-Salido, and Vallées (2003) examined the Federal Reserve’s response to VAR-identified technology shocks. They found that during the Martin-Burns- Miller era, the Federal Reserve responded to technology shocks by overstabilizing output, while in the Volcker-Greenspan era, the Federal Reserve adopted an inflation-targeting rule. We extend their analysis to countries of the G-7; moreover, we consider the factors that may contribute to differing monetary responses across countries. Specifically, we find a relationship between the volatility of capital investment, the type of monetary policy rule, the responsiveness of the rule to output and inflation fluctuations, and the response to technology shocks.price setting; nominal rigidity; real rigidity; inflation persistence; survey data

What Explains the Varying Monetary Response to Technology SHocks in G7-Countries

Structural vector autoregressions (SVARs) have become a standard tool used to determine the roles of monetary policy shocks in generating cyclical fluctuations in the United States. Using both long- and short-run identifying restrictions, various authors have explored the empirical response of the economy to exogenous monetary innovations. While the majority of the studies of monetary policy have focused on the effect of exogenous money growth or interest rate shocks, recent research has begun to investigate the effect of endogenous monetary policy -- that is, the central bank's reaction to non-monetary shocks. One exogenous shock that many economists believe contributes to the business cycle fluctuations that feed into the Taylor rule is the technology shock. In an effort to identify the empirical effects of technology shocks, Gali (1999) estimated two models: a bivariate model of productivity and hours and a five-variable model adding money, inflation, and interest rates. His identification estimates a decomposition of productivity and hours into innovations to technology and non-technology components by assuming that only the former can have long-run effects on labor productivity. Empirical identification of the technology shock was a key first step in developing a unified reduced-form framework with which to examine the role that monetary policy has played in smoothing economic fluctuations. Along these lines, Gali, Lopez-Salido, and Valles (2003 -- henceforth GLV) examined the endogenous response of monetary policy to identified technology shocks in the United States. GLV examine a four-variable structural VAR for the United States with labor productivity, labor hours, the real interest rate, and inflation. Using the Gali (1999) identification, they find that during the Volcker-Greenspan (VG) era the Fed's response to the technology shock is to raise the nominal interest rate, while during the Martin-Burns-Miller (MBM) era the Fed lowers the nominal rate. Moreover, they find that the inflation and hours responses in the two periods differ in sign. Our goal is to expand the scope of GLV to an international context to determine whether the effect of technology shocks is consistent across the major industrialized countries. In particular, we are interested in how the different central banks respond to technology shocks. We investigate the possibility that technology shocks in different countries produce fundamentally different inflation and employment responses and to what extent those effects alter the monetary response. Using a theoretical model adapted from King and Wolman (1996), we find that the empirical responses can be matched with theoretical responses. Differences in these theoretical responses can be attributed to alternative policy rules and changes in the cost of capital adjustment. Further tests verify that these country characteristics could, indeed, have some explanatory power. Our results are by no means conclusive; however, they do suggest a number of theoretically consistent similarities across countries in each subgroup. While we believe more investigation into these cross-country comparisons is warranted, the initial indication is that the manner in which monetary policy is conducted and the degree of rigidity in capital markets may be determining factors in a country's response to technology shocks. Gali, Jordi (1999). "Technology, Employment, and the Business Cycle: Do Technology Shocks Explain Aggregate Fluctuations?" American Economic Review, March 1999, 89(1), pp. 249-271. Gali, Jordi; Lopez-Salido, J. David; and Valles, Javier (2003). "Technology Shocks and Monetary Policy: Assessing the Fed's Performance." Journal of Monetary Economics, May 2003, 50(4), pp. 723-743. King, Robert G., and Wolman, Alexander L. (1996). "Inflation Targetting in a St. Louis Model of the 21st Century." Federal Reserve Bank of St. Louis Review, May/June 1996, 78(3), pp. 83-107.Technology, Productivity, Monetary Policy, Taylor Rule, Capital Adjustment Costs

Taphonomical observations on the pygmy hippopotamus site in Aghia Napa, Cyprus.

Στην εργασία αυτή παρουσιάζονται τα αποτελέσματα ταφονομικής ανάλυσης της Άνω πλειστοκαινικής θέσης της Αγίας Νάπας στην Κύπρο. Η πανίδα της απολιθωματοφόρου θέσης κυριαρχείται από σκελετικό υλικό νάνων ιπποπόταμων του είδους Phanourios minor, και εντοπίζεται κάτω από ένα φυσικό στέγαστρο εντός των ασβεστολιθικών σχηματισμών της περιοχής. Η εμφάνιση εκτείνεται σε μια περιοχή περίπου 72 τ.μ. από την οποία έχει συλλεχθεί ιδιαίτερα μεγάλος αριθμός ευρημάτων που υποδεικνύει την ύπαρξη περισσότερων από 160 ιπποπόταμων στη θέση. Στόχο της μελέτης αποτελεί και η απόδοση της αυξημένης συσσώρευσης του οστεολογικού υλικού σε συγκεκριμένους μηχανισμούς, εστιάζοντας στους παλαιοπεριβαλλοντικούς παράγοντες που πιθανά έχουν επηρεάσει και την επιβίωση του. Η ανάλυση στηρίζεται και σε παραμέτρους που μας πληροφορούν σχετικά με την αντιπροσώπευση και άρα την επιβίωση των διαφόρων σκελετικών στοιχείων. Η μελέτη του υλικού ανέδειξε την ύπαρξη λείανσης, κατακερματισμού και σημαντικής θραύσης, φαινόμενα που σχετίζονται με τον τύπο, το μέγεθος και το σχήμα των σκελετικών στοιχείων. Η συσσώρευση του υπό μελέτη υλικού ερμηνεύεται ως αποτέλεσμα φυσικής μεταφοράς τους στη θέση από την γύρω περιοχή, ενώ ο ρόλος του ανθρώπου σε αυτήν είναι ακόμη υπό διερεύνηση. In this paper data concerning the taphonomy of the Upper Pleistocene site Aghia Napa in Cyprus is presented. The site is dominated by skeletal material belonging to the pygmy Hippopotamus species Phanourios minor, and consists a littoral rockshelter. The fossiliferous assemblage is spread in a total area of about 72 m2 and a significantly large number of specimens were collected, indicating the presence of more than 160 individuals at the site. In this paper, we attempt to identify the causes or mechanisms that led to the accumulation of the endemic hippopotamus remains, focusing also on the palaeo-environmental parameters that might had affected the survivorship of the fossils. The taphonomical analysis is also based on parameters, which provide information concerning skeletal element representation and thus survivorship. The study of the skeletal material shows signs of abrasion, cracking and significant fragmentation which are related to the type, size and shape of the skeletal elements. The bone assemblage is interpreted as a result of transportation of the skeletal material from longer or shorter distances in the surrounding area while the impact of man concerning their accumulation is still under discussion

AgroCycle – developing a circular economy in agriculture

Continuing population growth and increasing consumption are driving global food demand, with agricultural activity expanding to keep pace. The modern agricultural system is wasteful, with Europe generating some 700 million tonnes of agrifood (agricultural and food) waste each year. The Agricultural Centre for Sustainable Energy Systems (ACSES) at Harper Adams University is involved in a major research and innovation project (AgroCycle) on the application of the ‘circular economy’ across the agri-food sector. In the context of the agrifood chain, the ‘circular economy’ aims to reduce waste while also making best use of the ‘wastes’ produced by using economically viable processes and procedures to increase their value . Led by University College Dublin, AgroCycle is a Horizon 2020 collaborative project with 26 partners. AgroCycle will address such opportunities directly by implementation of the ‘circular economy’ across the agri-food sector. The authors will present (a) a summary of the AgroCycle project and (b) the role played by Harper Adams in the project in evaluating the potential for small-scale anaerobic digestion (AD) technology that can be applied on farm to provide local heat, energy and nutrient recovery from mixed agricultural wastes

Numerical renormalization-group study of spin correlations in one-dimensional random spin chains

We calculate the ground-state two-spin correlation functions of spin-1/2 quantum Heisenberg chains with random exchange couplings using the real-space renormalization group scheme. We extend the conventional scheme to take account of the contribution of local higher multiplet excitations in each decimation step. This extended scheme can provide highly accurate numerical data for large systems. The random average of staggered spin correlations of the chains with random antiferromagnetic (AF) couplings shows algebraic decay like $1/r^2$, which verifies the Fisher's analytic results. For chains with random ferromagnetic (FM) and AF couplings, the random average of generalized staggered correlations is found to decay more slowly than a power-law, in the form close to $1/\ln(r)$. The difference between the distribution functions of the spin correlations of the random AF chains and of the random FM-AF chains is also discussed.Comment: 14 pages including 8 figures, REVTeX, submitted to Physical Review

Anomalous pinning behavior in an incommensurate two-chain model of friction

Pinning phenomena in an incommensurate two-chain model of friction are studied numerically. The pinning effect due to the breaking of analyticity exists in the present model. The pinning behavior is, however, quite different from that for the breaking of analyticity state of the Frenkel-Kontorova model. When the elasticity of chains or the strength of interchain interaction is changed, pinning force and maximum static frictional force show anomalously complicated behavior accompanied by a successive phase transition and they vanish completely under certain conditions.Comment: RevTex, 9 pages, 19 figures, to appear in Phys. Rev. B58 No.23(1998