Strategic Asset Allocation, Asset Price Dynamics, and the Business Cycle

The main contribution of this work is to provide a dynamic general equilibrium model of asset allocation, allowing to reconcile economic theory with several puzzling contradictions recently pointed out in the literature: (i) the asset allocation puzzle, (ii) the observed time-variation in aggregate portfolio holdings, and (iii) the occurrence of twin peaks in equity and house prices. In this approach, compared to the existing literature, the main difference stems from the fact that, in addition to consumption and dividends, both prices and portfolio decisions are allowed to be endogenously determined within a general equilibrium framework. Secondly, real estate is introduced into the analysis, labor supply is allowed to be endogenously determined and macroeconomic shocks are the main source of riskiness.strategic asset allocation, real estate, house prices, business cycle, general equilibrium

EDUCATIONAL ACTIVITIES ON WATER RESOURCES IN KANSAS

Resource /Energy Economics and Policy,

Asset pricing, habit memory, and the labor market

This article studies the asset pricing and the business cycle implications of habit formation in a production economy with capital adjustment costs and endogenous labor supply. A specification of internal habit in the mix of consumption and leisure which minimizes the wealth effect on labor supply is introduced into an otherwise standard real business cycle model. This mechanism enhances the model’s ability to explain asset pricing puzzles. JEL Classification: G12, E32, J22adjustment costs, equity premium puzzle, Labor supply

POLICY WORK WITH WOMEN'S GROUPS IN KANSAS

Agricultural and Food Policy,

Probing the phase diagram of CeRu_2Ge_2 by thermopower at high pressure

The temperature dependence of the thermoelectric power, S(T), and the electrical resistivity of the magnetically ordered CeRu_2Ge_2 (T_N=8.55 K and T_C=7.40 K) were measured for pressures p < 16 GPa in the temperature range 1.2 K < T < 300 K. Long-range magnetic order is suppressed at a p_c of approximately 6.4 GPa. Pressure drives S(T) through a sequence of temperature dependences, ranging from a behaviour characteristic for magnetically ordered heavy fermion compounds to a typical behaviour of intermediate-valent systems. At intermediate pressures a large positive maximum develops above 10 K in S(T). Its origin is attributed to the Kondo effect and its position is assumed to reflect the Kondo temperature T_K. The pressure dependence of T_K is discussed in a revised and extended (T,p) phase diagram of CeRu_2Ge_2.Comment: 7 pages, 6 figure

Estimating the Effect of the Canadian Government's 2006-2007 Greenhouse Gas Policies

Mounting public concern about climate change has prompted the Canadian government to respond with a major policy effort to reduce greenhouse gas (GHG) emissions. Since early 2006, the Conservative government has launched a series of initiatives under its “ecoACTION” banner, culminating in the release in April 2007 of its “regulatory framework for air emissions,” which is currently under consultative review.economic growth, economic innovation

A non-local theory of massive gravity

We construct a fully covariant theory of massive gravity which does not require the introduction of an external reference metric, and overcomes the usual problems of massive gravity theories (fatal ghosts instabilities, acausality and/or vDVZ discontinuity). The equations of motion of the theory are non-local, but respect causality. The starting point is the quadratic action proposed in the context of the degravitation idea. We show that it is possible to extended it to a fully non-linear covariant theory. This theory describes the five degrees of freedom of a massive graviton plus a scalar ghost. However, contrary to generic non-linear extensions of Fierz-Pauli massive gravity, the ghost has the same mass m as the massive graviton, independently of the background, and smoothly goes into a non-radiative degree of freedom for m-> 0. As a consequence, for $m\sim H_0$ the vacuum instability induced by the ghost is irrelevant even over cosmological time-scales. We finally show that an extension of the model degravitates a vacuum energy density of order $M_{Planck}^4$ down to a value of order $M_{Planck}^2 m^2$, which for $m \sim H_0$ is of order of the observed value of the vacuum energy density.Comment: 45 pages, 2 figs; v2: references and comments added. To appear in PR

Valence fluctuation mediated superconductivity in CeCu2Si2

It has been proposed that there are two types of superconductivity in CeCu2Si2, mediated by spin fluctuations at ambient pressure, and by critical valence fluctuations around a charge instability at a pressure P_v \simeq 4.5 GPa. We present in detail some of the unusual features of this novel type of superconducting state, including the coexistence of superconductivity and huge residual resistivity of the order of the Ioffe-Regel limit, large and pressure dependent resistive transition widths in a single crystal measured under hydrostatic conditions, asymmetric pressure dependence of the specific heat jump shape, unrelated to the resistivity width, and negative temperature dependence of the normal state resistivity below 10 K at very high pressure.Comment: 4 pages, 4 figures; Proceedings SCES '0

Valence Instability and Superconductivity in Heavy Fermion Systems

Many cerium-based heavy fermion (HF) compounds have pressure-temperature phase diagrams in which a superconducting region extends far from a magnetic quantum critical point. In at least two compounds, CeCu2Si2 and CeCu2Ge2, an enhancement of the superconducting transition temperature was found to coincide with an abrupt valence change, with strong circumstantial evidence for pairing mediated by critical valence, or charge transfer, fluctuations. This pairing mechanism, and the valence instability, is a consequence of a f-c Coulomb repulsion term U_fc in the hamiltonian. While some non-superconducting Ce compounds show a clear first order valence instability, analogous to the Ce alpha-gamma transition, we argue that a weakly first order valence transition may be a general feature of Ce-based HF systems, and both magnetic and critical valence fluctuations may be responsible for the superconductivity in these systems.Comment: 11 pages, 16 figure

Early dark energy from zero-point quantum fluctuations

We examine a cosmological model with a dark energy density of the form $\rho_{DE}(t)=\rho_X(t)+\rho_Z(t)$, where $\rho_X$ is the component that accelerates the Hubble expansion at late times and $\rho_Z(t)$ is an extra contribution proportional to $H^2(t)$. This form of $\rho_Z(t)$ follows from the recent proposal that the contribution of zero-point fluctuations of quantum fields to the total energy density should be computed by subtracting the Minkowski-space result from that computed in the FRW space-time. We discuss theoretical arguments that support this subtraction. By definition, this eliminates the quartic divergence in the vacuum energy density responsible for the cosmological constant problem. We show that the remaining quadratic divergence can be reabsorbed into a redefinition of Newton's constant only under the assumption that the energy-momentum tensor of vacuum fluctuations is conserved in isolation. However, in the presence of an ultra-light scalar field $X$ with $m_X<H_0$, as typical of some dark energy models, the gravity effective action depends both on the gravitational field and on the $X$ field. In this case general covariance only requires the conservation of the total energy-momentum tensor, including both the classical term $T^X_{\mu\nu}$ and the vacuum expectation value of T_{\mu\nu}. If there is an exchange of energy between these two terms, there are potentially observable consequences. We construct an explicit model with an interaction between $\rho_X$ and $\rho_Z$ and we show that the total dark energy density $\rho_{DE}(t)=\rho_X(t)+\rho_Z(t)$ always remains a finite fraction of the critical density at any time, providing a specific model of early dark energy. We discuss the implication of this result for the coincidence problem and we estimate the model parameters by means of a full likelihood analysis using current CMB, SNe Ia and BAO data.Comment: 7 pages, 3 figures; v3: improved discussion, references adde