Royal Road to Coupling Classical and Quantum Dynamics

We present a consistent framework of coupled classical and quantum dynamics. Our result allows us to overcome severe limitations of previous phenomenological approaches, like evolutions that do not preserve the positivity of quantum states or that allow to activate quantum nonlocality for superluminal signaling. A `hybrid' quantum-classical density is introduced and its evolution equation derived. The implications and applications of our result are numerous: it incorporates the back-reaction of quantum on classical variables, it resolves fundamental problems encountered in standard mean field theories, and remarkably, also the quantum measurement process, i.e. the most controversial example of quantum-classical interaction is consistently described within our approach, leading to a theory of dynamical collapse.Comment: 4 pages, RevTe

Exact Relations between Four De?nitions of Productivity Indices and Indicators

Generalizing earlier approximation results, we establish exact relations between the Luenberger productivity indicator and the Malmquist productivity index under rather mild assumptions. Furthermore, we show that similar exact relations can be established between the Luenberger-Hicks-Moorsteen indicator and the Hicks-Moorsteen index.Malmquist and Hicks-Moorsteen productivity indices, Luenberger and Luenberger Hicks-Moorsteen productivity indicators, approximate relation, exact relation

The Distribution of Stellar Orbits in the Giant Elliptical Galaxy NGC 2320

We present direct observational constraints on the orbital distribution of the stars in the giant elliptical NGC 2320. Long-slit spectra along multiple position angles are used to derive the stellar line-of-sight velocity distribution within one effective radius. In addition, the rotation curve and dispersion profile of an ionized gas disk are measured from the [OIII] emission lines. After correcting for the asymmetric drift, we derive the circular velocity of the gas, which provides an independent constraint on the gravitational potential. To interpret the stellar motions, we build axisymmetric three-integral dynamical models based on an extension of the Schwarzschild orbit- superposition technique. We consider two families of gravitational potential, one in which the mass follows the light (i.e. no dark matter) and one with a logarithmic gravitational potential. Using chi^2-statistics, we compare our models to both the stellar and gas data to constrain the value of the V-band mass-to-light ratio Upsilon-V. We find Upsilon-V = 15.0 \pm 0.6 h75 for the mass-follows-light models and Upsilon-V = 17.0 \pm 0.7 h75 for the logarithmic models. For the latter, Upsilon-V is defined within a sphere of 15'' radius. Models with radially constant Upsilon-V and logarithmic models with dark matter provide comparably good fits to the data and possess similar dynamical structure. Across the full range of Upsilon-V permitted by the observational constraints, the models are radially anisotropic in the equatorial plane over the radial range of our kinematical data (1'' < r < 40''). Along the true minor axis, they are more nearly isotropic. (abridged)Comment: 26 pages, 13 figures, accepted for publication in the Astrophysical Journa

Productivity Growth and Biased Technological Change in Hydroelectric Generating Dams

This paper analyses productivity growth and the nature of techni- cal change in a sample of Portuguese hydroelectric generating plants over the period 2001 to 2004. In a ¯rst step, we employ the Luen- berger productivity indicator to estimate and decompose productivity change. The results paint a picture of mixed productivity performance in the Portuguese energy sector. In a second step, we analyse the na- ture of this technical change by using the recent concept of parallel neutrality (Briec et al., 2006). We observe a global shift in the best practice frontier as well as evidence of input bias in technical change.hydroelectric energy; Portugal; Luenberger productivity indicator; parallel neutrality.

Can Microfinance Reduce Portfolio Volatility?

Microfinance is arguably one of the most effective techniques for poverty alleviation in developing countries. Although traditionally supported by nongovernmental organizations and socially-oriented investors, microfinance institutions (MFIs) have increasingly demonstrated their value on a stand-alone basis, typically exhibiting low default rates combined with attractive returns and growth, encouraging greater commercial involvement. This paper addresses a related issue whether microfinance shows low correlation with international and domestic market performance measures. If so, it could form the empirical basis for MFI access to capital markets and performance-driven investors in their search for efficient portfolios. Our empirical tests do not show any exposure of microfinance institutions to global capital markets, but significant exposure regarding domestic GDP, suggesting that microfinance investments may have useful portfolio diversification value for international investors, not for domestic investors lacking significant country risk diversification options

Does Microfinance Form a Distinctive Asset Class? Preliminary Evidence

Microfinance is arguably one of the most effective techniques for poverty alleviation in developing countries. Although traditionally supported by nongovernmental organizations and socially-oriented investors, microfinance has increasingly demonstrated its value on a stand-alone basis, typically exhibiting low default rates combined with attractive returns, encouraging greater commercial involvement. This paper addresses a related issue whether microfinance represents a distinct financial asset class, thereby forming the basis for access to global capital markets and performance-driven investors in their search for efficient portfolios. Our empirical tests generally show very low correlations between the performance of microfinance institutions and global and national market performance measures, suggesting that microfinance portfolios may constitute a distinct asset class that can have useful portfolio diversification value

Can Microfinance Reduce Portfolio Volatility?

Microfinance is arguably one of the most effective techniques for poverty alleviation in developing countries. Although traditionally supported by nongovernmental organizations and socially-oriented investors, microfinance institutions (MFIs) have increasingly demonstrated their value on a stand-alone basis, typically exhibiting low default rates combined with attractive returns and growth, encouraging greater commercial involvement. This paper addresses a related issue – whether microfinance shows low correlation with international and domestic market performance measures. If so, it could form the empirical basis for MFI access to capital markets and performance-driven investors in their search for efficient portfolios. Our empirical tests do not show any exposure of microfinance institutions to global capital markets, but significant exposure regarding domestic GDP, suggesting that microfinance investments may have useful portfolio diversification value for international investors, not for domestic investors lacking significant country risk diversification options