Off-shoring and productivity growth in the Italian manufacturing industries

We employ input-output tables to study the relation between off-shoring and productivity growth in the Italian manufacturing industries in 1995-2003. Our results indicate that not all types of off-shoring are positively related to productivity growth. In particular, the international outsourcing of intermediates within the same industry (“narrow off-shoring”) is beneficial for productivity growth, while the off-shoring of services is not. We also find that the way in which off-shoring is measured may matter considerably. The positive relation between off-shoring of intermediates and productivity growth disappears when our direct measure of off-shoring is replaced with the Feenstra-Hanson measure employed in other studies.International trade, Productivity growth; offshoring; Italian economy

Italy’s decline: getting the facts right

The Italian economy is often said to be on a declining path. In this paper, we document that: (i) Italy’s current decline is a labor productivity problem (ii) the labor productivity slowdown stems from declining productivity growth in all industries but utilities (with manufacturing contributing for about one half of the reduction) and diminished interindustry reallocation of workers from agriculture to market services; (iii) the labor productivity slowdown has been mostly driven by declining TFP, with roughly unchanged capital deepening. The only mild decline of capital deepening is due to the rise in the value added share of capital that counteracted declining capital accumulation.Productivity growth, Productivity slowdown, TFP, decline, Italy

Effective Constraints and Physical Coherent States in Quantum Cosmology: A Numerical Comparison

A cosmological model with a cyclic interpretation is introduced, which is subject to quantum back-reaction and yet can be treated rather completely by physical coherent state as well as effective constraint techniques. By this comparison, the role of quantum back-reaction in quantum cosmology is unambiguously demonstrated. Also the complementary nature of strengths and weaknesses of the two procedures is illustrated. Finally, effective constraint techniques are applied to a more realistic model filled with radiation, where physical coherent states are not available.Comment: 32 pages, 25 figure

Giant electrocaloric effect around Tc_c

We use molecular dynamics with a first-principles-based shell model potential to study the electrocaloric effect (ECE) in lithium niobate, LiNbO$_3$, and find a giant electrocaloric effect along a line passing through the ferroelectric transition. With applied electric field, a line of maximum ECE passes through the zero field ferroelectric transition, continuing along a Widom line at high temperatures with increasing field, and along the instability that leads to homogeneous ferroelectric switching below $T_c$ with an applied field antiparallel to the spontaneous polarization. This line is defined as the minimum in the inverse capacitance under applied electric field. We investigate the effects of pressure, temperature and applied electric field on the ECE. The behavior we observe in LiNbO$_3$ should generally apply to ferroelectrics; we therefore suggest that the operating temperature for refrigeration and energy scavenging applications should be above the ferroelectric transition region to obtain large electrocaloric response. We find a relationship among $T_c$, the Widom line and homogeneous switching that should be universal among ferroelectrics, relaxors, multiferroics, and the same behavior should be found under applied magnetic fields in ferromagnets.Comment: 5 page

An exact representation of the fermion dynamics in terms of Poisson processes and its connection with Monte Carlo algorithms

We present a simple derivation of a Feynman-Kac type formula to study fermionic systems. In this approach the real time or the imaginary time dynamics is expressed in terms of the evolution of a collection of Poisson processes. A computer implementation of this formula leads to a family of algorithms parametrized by the values of the jump rates of the Poisson processes. From these an optimal algorithm can be chosen which coincides with the Green Function Monte Carlo method in the limit when the latter becomes exact.Comment: 4 pages, 1 PostScript figure, REVTe

Origin of Large Dielectric Constant with Large Remnant Polarization and Evidence of Magnetoelectric Coupling in Multiferroic La modified BiFeO3-PbTiO3 Solid Solution

The presence of superlattice reflections and detailed analyses of the powder neutron and x-ray diffraction data reveal that La rich (BF$_{0.50}$-LF$_{0.50}$)$_{0.50}$-(PT)$_{0.50}$ (BF-LF-PT) has ferroelectric rhombohedral crystal structure with space group \textit{$R3c$} at ambient conditions. The temperature dependence of lattice parameters, tilt angle, calculated polarization $(P_{s})$, volume, and integrated intensity of superlattice and magnetic reflections show an anomaly around 170 K. Impedance spectroscopy, dielectric and ac conductivity measurements were performed in temperature range $473K \leq T \leq 573K$ to probe the origin of large remnant polarization and frequency dependent broad transitions with large dielectric constant near $T_c^{FE}$. Results of impedance spectroscopy measurements clearly show contributions of both grain and grain boundaries throughout the frequency range ($10^{3}$ Hz$\leq f\leq 10^{7}$ Hz). It could be concluded that the grain boundaries are more resistive and capacitive as compared to the grains, resulting in inhomogeneities in the sample causing broad frequency dependent dielectric anomalies. Enhancement in dielectric constant and remnant polarization values are possibly due to space charge polarization caused by piling of charges at the interface of grains and grain boundaries. The imaginary parts of dielectric constant ($\epsilon^{\prime\prime}$) Vs frequency data were fitted using Maxwell-Wagner model at $T_c^{FE}(\sim 523$K) and model fits very well with the data up to $10^{5}$ Hz. Magnetodielectric measurements prove that the sample starts exhibiting magnetoelectric coupling at $\sim 170$ K, which is also validated by neutron diffraction data.Comment: 20 pages, 10 figure

Self-bound many-body states of quasi-one-dimensional dipolar Fermi gases: Exploiting Bose-Fermi mappings for generalized contact interactions

Using a combination of results from exact mappings and from mean-field theory we explore the phase diagram of quasi-one-dimensional systems of identical fermions with attractive dipolar interactions. We demonstrate that at low density these systems provide a realization of a single-component one-dimensional Fermi gas with a generalized contact interaction. Using an exact duality between one-dimensional Fermi and Bose gases, we show that when the dipole moment is strong enough, bound many-body states exist, and we calculate the critical coupling strength for the emergence of these states. At higher densities, the Hartree-Fock approximation is accurate, and by combining the two approaches we determine the structure of the phase diagram. The many-body bound states should be accessible in future experiments with ultracold polar molecules

Fragile phase stability in (1-x)Pb(Mg1/3Nb2/3O3)-xPbTiO3 crystals: A comparisons of [001] and [110] field-cooled phase diagrams

Phase diagrams of [001] and [110] field-cooled (FC) (1-x)Pb(Mg1/3Nb2/3O3)-xPbTiO3 or PMN-xPT crystals have been constructed, based on high-resolution x-ray diffraction data. Comparisons reveal several interesting findings. First, a region of abnormal thermal expansion above the dielectric maximum was found, whose stability range extended to higher temperatures by application of electric field (E). Second, the rhombohedral (R) phase of the ZFC state was replaced by a monoclinic MA in the [001] FC diagram, but with monoclinic MB in the [110] FC. Third, the monoclinic MC phase in ZFC and [001] FC diagram was replaced by an orthorhombic (O) phase in the [110] FC. Finally, in the [001] FC diagram, the phase boundary between tetragonal (T) and MA was extended to lower PT contents (x=0.25); whereas in the [110] FC diagram, this extended region was entirely replaced by the O phase. These results clearly demonstrate that the phase stability of PMN-xPT crystals is quite fragile, depending not only on modest changes in E, but also on the direction along which that E is applied.Comment: 13 pages, 8 figures, 1 tabl