Systems-Disconjugacy of a Fourth-Order Differential Equation with a Middle Term

Systems-conjugate points have been introduced and studied by John Barrett \cite{barr} in relation with the self-adjoint fourth order differential equation $$(r(x)y")"-(q(x)y')'= p(x)y,$$ where $r(x)>0$, $p(x)>0$ and $q\equiv0$. In this paper we extend some of his results to more general cases, when $q(x)$ is free of any sign restrictions.Comment: 13 pages, 0 figure

Exchange Rate Dynamics and Fundamental Equilibrium Exchange Rates

The paper investigates if the most popular alternative to the purchasing parity power approach (PPP) to estimate equilibrium exchange rates, the fundamental equilibrium exchange rate (FEER) influences exchange rate dynamics in the long run. For a large panel of industrialized and emerging countries and on the period 1982-2007, we detect the presence of unit roots in the series of real effective exchange rates and in the series of FEERs. We find and estimate a cointegration relationship between real effective exchange rates and FEERs. The results show that the FEER has a positive and significant influence on exchange rate dynamics in the long run.Fundamental equilibrium exchange rates; Panel unit root tests; Global imbalances; Fully modified ordinary least square; Dynamic ordinary least square; Pooled Mean Group

Global imbalances and capital account openness: an empirical analysis

We investigate if capital account openness has played a major role in the evolution of global imbalances on the period 1980-2003. We estimate, with panel regression techniques, the impact of capital account openness on medium run current account imbalances for industrialized and emerging countries by using a de jure measure of capital account openness (the Chinn-Ito index of capital account openness, 2002, 2006) and a de facto measure of capital account openness (the gross foreign assets measured as the sum of foreign assets and foreign liabilities). By increasing the opportunities of overseas investments, the relative capital account openness has had positive impact on medium run current account balances of industrialized countries (because of downward pressures on domestic investment rates). Conversely, the relative capital account openness has had negative impact on medium run current account balances of emerging countries (because of upward pressures on domestic investment rates). The evolutions of domestic and foreign capital account openness have allowed increasing medium run current account balances in absolute value during this period.Global Imbalances; Capital Account Openness; Chinn-Ito index

Exchange Rate Dynamics and Fundamental Equilibrium Exchange Rates

The paper investigates if the most popular alternative to the purchasing parity power approach (PPP) to estimate equilibrium exchange rates, the fundamental equilibrium exchange rate (FEER) influences exchange rate dynamics in the long run. For a large panel of industrialized and emerging countries and on the period 1982-2007, we detect the presence of unit roots in the series of real effective exchange rates and in the series of FEERs. We find and estimate a cointegration relationship between real effective exchange rates and FEERs. The results show that the FEER has a positive and significant influence on exchange rate dynamics in the long run.Fundamental equilibrium exchange rates, Panel unit root tests, Global imbalances, Fully modified ordinary least square, Dynamic ordinary least square

Global existence of the two-dimensional QGE with sub-critical dissipation

In this paper, we study the sub-critical dissipative quasi-geostrophic equations $({\bf S}_\alpha)$. We prove that there exists a unique local-in-time solution for any large initial data $\theta_0$ in the space ${\bf{\mathcal X}}^{1-2\alpha}(\mathbb R^2)$ defined by (\ref{ec}). Moreover we show that $({\bf S}_\alpha)$ has a global solution in time if the norms of the initial data in ${\bf{\mathcal X}}^{1-2\alpha}(\mathbb R^2)$ are bounded by $1/4$. Also, we prove a blow-up criterion of the non global solution of $({\bf S}_\alpha)$.Comment: 16 page