Welfare Implications of Exchange Rate Changes

This paper measures the welfare implications of a depreciation of the US dollar against the euro using a dynamic equilibrium model. I calibrate a simple two country stochastic endowment economy with trade in goods and financial assets and exogenous variations in the exchange rate. The model displays both a trade channel effect and an asset channel effect after a change in the value of the exchange rate. The welfare loss coming from the trade channel translates into the relatively higher price that consumers have to pay for imports. The asset channel effect arises from three sources. One is the traditional valuation effect associated with US debt being denominated mostly in dollars. The other two novel effects are: (1) the dollar value of investors net worth, mostly denominated in local currency, increases more in Europe than in the US; (2) asset prices change, causing a portfolio rebalancing effect which results in a fall in the share of world assets owned by the US. I show that a dollar depreciation has potentially large negative welfare effects as measured by the net present value of future consumption. After a temporary 10% depreciation of the dollar, with a half-life of one year, I calculate a 0.25% decrease in lifetime aggregate consumption for the US consumer.trade effect, valuation effect, wealth effect, exchange rate, dynamic equilibrium model, welfare

Roper Electroproduction Amplitudes in a Chiral Confinement Model

A description of the Roper using the chiral chromodielectric model is presented and the transverse $A_{1/2}$ and the scalar $S_{1/2}$ helicity amplitudes for the electromagnetic Nucleon--Roper transition are obtained for small and moderate $Q^2$. The sign of the amplitudes is correct but the model predictions underestimate the data at the photon point. Our results do not indicate a change of sign in any amplitudes up to $Q^2\sim1$ GeV$^2$. The contribution of the scalar meson excitations to the Roper electroproduction is taken into account but it turns out to be small in comparison with the quark contribution. However, it is argued that mesonic excitations may play a more prominent role in higher excited states.Comment: 10 pages, 8 figures, uses World Scientific macros. Talk presented at EMI2001 in Osaka, Japa

Bayesian Analysis of Simple Random Densities

A tractable nonparametric prior over densities is introduced which is closed under sampling and exhibits proper posterior asymptotics.Comment: 19 pages; 6 figure

Cross-sectional and prospective impact of reallocating sedentary time to physical activity on children's body composition.

BACKGROUND: The amount of time children spend in sedentary behaviours may have adverse health effects. OBJECTIVE: To examine the substitution effects of displacing a fixed duration of sedentary time with physical activity (PA) on children's body composition. METHODS: We included 386 children (197 boys). Outcomes were body mass index, waist circumference, total body fat mass and trunk fat mass assessed by dual-energy X-ray absorptiometry. Sedentary time and PA were measured with accelerometers. Data were analysed by isotemporal analyses estimating the effect of reallocating 15 and 30 min d-1 of sedentary time into light (light physical activity), and moderate-to-vigorous (MVPA) PA on body composition. RESULTS: Reallocating 15 and 30 min d-1 of sedentary time into MVPA was negatively associated with body fatness in cross-sectional analyses. Prospectively, reallocating 30 min of sedentary time into 30 min of MVPA was negatively associated with waist circumference (β = -1.11, p  0.05) with body fatness outcomes. CONCLUSIONS: Substituting sedentary time with MVPA using isotemporal analysis is associated with positive effects on body composition