Temptation and Self-Control: Some Evidence from the Consumer Expenditure Survey

Temptation, Self-Control, Gul-Pesendorfer Preferences, Asset Pricing

Vertical production and trade interdependence and welfare

The authors study international transmissions and welfare implications of monetary shocks in a two-country world with multiple stages of production and multiple border-crossings of intermediate goods. This empirically relevant feature is important, as it has opposite implications for two external spillover effects of a unilateral monetary expansion. If all production and trade are assumed to occur in a single stage, the conflict-of-interest terms-of-trade effect tends to dominate the common-interest efficiency-improvement effect for reasonable parameter values, so that the international welfare effects would depend in general on the underlying assumptions about the currencies of price setting. The stretch of production and trade across multiple stages of processing magnifies the efficiency-improvement effect and dampens the terms-of-trade effect. Thus, a monetary expansion can be mutually beneficial regardless of its source or the pricing assumptions.Production (Economic theory) ; Trade ; Monopolistic competition ; Welfare

Learning, adaptive expectations, and technology shocks

This study explores the macroeconomic implications of adaptive expectations in a standard real business cycle model. When rational expectations are replaced by adaptive expectations, we show that the self-confirming equilibrium is the same as the steady-state rational expectations equilibrium for all admissible parameters but that dynamics around the steady state are substantially different between the two equilibria. The differences are driven mainly by the dampened wealth effect and the strengthened intertemporal substitution effect, not by the escapes emphasized by Williams (2003). As a result, adaptive expectations can be an important source of frictions that amplify and propagate technology shocks and seem promising for generating plausible labor market dynamics.Equilibrium (Economics)

Learning, adaptive expectations, and technology shocks

This study explores the macroeconomic implications of adaptive expectations in a standard real business cycle model. When rational expectations are replaced by adaptive expectations, we show that the self-confirming equilibrium is the same as the steady state rational expectations equilibrium for all admissible parameters, but that dynamics around the steady state are substantially different between the two equilibria. The differences are driven mainly by the dampened wealth effect and the strengthened intertemporal substitution effect, not by the escapes emphasized by Williams (2003). As a result, adaptive expectations can be an important source of frictions that amplify and propagate technology shocks and seem promising for generating plausible labor market dynamics.Macroeconomics

On Two-Body Decays of A Scalar Glueball

We study two body decays of a scalar glueball. We show that in QCD a spin-0 pure glueball (a state only with gluons) cannot decay into a pair of light quarks if chiral symmetry holds exactly, i.e., the decay amplitude is chirally suppressed. However, this chiral suppression does not materialize itself at the hadron level such as in decays into $\pi^+\pi^-$ and $K^+K^-$, because in perturbative QCD the glueball couples to two (but not one) light quark pairs that hadronize to two mesons. Using QCD factorization based on an effective Lagrangian, we show that the difference of hadronization into $\pi\pi$ and $KK$ already leads to a large difference between ${\rm Br} (\pi^+\pi^-)$ and ${\rm Br}(K^+K^-)$, even the decay amplitude is not chirally suppressed. Moreover, the small ratio of $R={\rm Br}(\pi\pi)/{\rm Br}(K\bar K)$ of $f_0(1710)$ measured in experiment does not imply $f_0(1710)$ to be a pure glueball. With our results it is helpful to understand the partonic contents if ${\rm Br}(\pi\pi)$ or ${\rm Br}(K\bar K)$ is measured reliably.Comment: revised versio

Properties and Performance of Two Wide Field of View Cherenkov/Fluorescence Telescope Array Prototypes

A wide field of view Cherenkov/fluorescence telescope array is one of the main components of the Large High Altitude Air Shower Observatory project. To serve as Cherenkov and fluorescence detectors, a flexible and mobile design is adopted for easy reconfiguring of the telescope array. Two prototype telescopes have been constructed and successfully run at the site of the ARGO-YBJ experiment in Tibet. The features and performance of the telescopes are presented

Projected SO(5) Hamiltonian for Cuprates and Its Applications

The projected SO(5) (pSO(5)) Hamiltonian incorporates the quantum spin and superconducting fluctuations of underdoped cuprates in terms of four bosons moving on a coarse grained lattice. A simple mean field approximation can explain some key feautures of the experimental phase diagram: (i) The Mott transition between antiferromagnet and superconductor, (ii) The increase of T_c and superfluid stiffness with hole concentration x and (iii) The increase of antiferromagnetic resonance energy as sqrt{x-x_c} in the superconducting phase. We apply this theory to explain the ``two gaps'' problem found in underdoped cuprate Superconductor-Normal- Superconductor junctions. In particular we explain the sharp subgap Andreev peaks of the differential resistance, as signatures of the antiferromagnetic resonance (the magnon mass gap). A critical test of this theory is proposed. The tunneling charge, as measured by shot noise, should change by increments of Delta Q= 2e at the Andreev peaks, rather than by Delta Q=e as in conventional superconductors.Comment: 3 EPS figure

Input-Output Structure and the General Equilibrium Dynamics of Inflation and Output

Recent empirical studies reveal that monetary shocks cause persistent fluctuations in inflation and aggregate output. In the literature, few mechanisms have been identified to generate such persistence. In this paper, we propose a new mechanism that does so. Our model features an input-output structure and staggered price contracts. Working through the input-output relations and the timing of firms\u27 pricing decisions, the model generates smaller fluctuations in marginal cost facing firms at later stages than at earlier stages and hence persistent responses of both the inflation rate and aggregate output following a monetary stock. The persistence is larger, the greater the number of production stages. With a sufficient number of stages, the real persistence is arbitrarily large

Direct Measurements of Absolute Branching Fractions for D0 and D+ Inclusive Semimuonic Decays

By analyzing about 33 $\rm pb^{-1}$ data sample collected at and around 3.773 GeV with the BES-II detector at the BEPC collider, we directly measure the branching fractions for the neutral and charged $D$ inclusive semimuonic decays to be $BF(D^0 \to \mu^+ X) =(6.8\pm 1.5\pm 0.7)$ and $BF(D^+ \to \mu^+ X) =(17.6 \pm 2.7 \pm 1.8)$, and determine the ratio of the two branching fractions to be $\frac{BF(D^+ \to \mu^+ X)}{BF(D^0 \to \mu^+ X)}=2.59\pm 0.70 \pm 0.25$

A study of charged kappa in J/ψ→K±Ksπ∓π0J/\psi \to K^{\pm} K_s \pi^{\mp} \pi^0

Based on $58 \times 10^6$ $J/\psi$ events collected by BESII, the decay $J/\psi \to K^{\pm} K_s \pi^{\mp} \pi^0$ is studied. In the invariant mass spectrum recoiling against the charged $K^*(892)^{\pm}$, the charged $\kappa$ particle is found as a low mass enhancement. If a Breit-Wigner function of constant width is used to parameterize the kappa, its pole locates at $(849 \pm 77 ^{+18}_{-14}) -i (256 \pm 40 ^{+46}_{-22})$ MeV/$c^2$. Also in this channel, the decay $J/\psi \to K^*(892)^+ K^*(892)^-$ is observed for the first time. Its branching ratio is $(1.00 \pm 0.19 ^{+0.11}_{-0.32}) \times 10^{-3}$.Comment: 14 pages, 4 figure