Testing Non-nested Demand Relations: Linear Expenditure System versus Indirect Addilog

In applied economic research computable general equilibrium [CGE] models in which the behavior of economic agents are modeled, are widely used. In many CGE models, the Linear Expenditure System [LES] is used to model behavior of the household sector. The disadvantage of LES is that the Engel curves, describing the relationship between expenditure on a certain commodity and total expenditure, are straight lines. Moreover, the LES does not allow for the existence of inferior commodities, elastic demand and gross substitution. An alternative model for the household block is the Indirect Addilog System [IAS] which is as simple to implement as LES, but which does not suffer from these theoretical deficiencies. Consequently, IAS provides a theoretically richer description of household behavior than LES, while it is as easy to implement. In this paper we test the LES specification against the IAS specification in case one disposes of a budget survey. It is not possible to use a standard likelihood ratio test as both models are not nested. We propose to use the likelihood ratio test for non-nested hypotheses due to Vuong (1989), or, alternatively, the distribution-free test due to Clarke (2007). We apply both tests to the Palestinian Expenditure and Consumption Survey (PECS, 2005) and find that there is overwhelming evidence that the IAS specification is to be preferred to the LES specification

Self consistent propagation of hyperons and antikaons in nuclear matter based on relativistic chiral SU(3) dynamics

We evaluate the antikaon spectral density in isospin symmetric nuclear matter. The in-medium antikaon-nucleon scattering process and the antikaon propagation is treated in a self consistent and relativistic manner where a maximally scheme-independent formulation is derived by performing a partial density resummation in terms of the free-space antikaon-nucleon scattering amplitudes. The latter amplitudes are taken from a relativistic and chiral coupled-channel SU(3) approach which includes s-, p- and d-waves systematically. Particular care is taken on the proper evaluation of the in-medium mixing of the partial waves. Our analysis establishes a rich structure of the antikaon spectral function with considerable strength at small energies. At nuclear saturation density we predict attractive mass shifts for the #LAMBDA#(1405), #SIGMA#(1385) and #LAMBDA#(1520) of about 130 MeV, 60 MeV and 100 MeV respectively. The hyperon states are found to exhibit at the same time an increased decay width of about 150 MeV for the s-wave #LAMBDA#(1405), 70 MeV for the p-wave #SIGMA#(1385) and 100 MeV for the d-wave #LAMBDA#(1520) resonance. (orig.)Available from TIB Hannover: RO 801(2001-18) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Self consistent and covariant propagation of pions, nucleon and isobar resonances in cold nuclear matter

We evaluate the in-medium spectral functions for pions, nucleon and isobar resonances in a self consistent and covariant manner. The calculations are based on a recently developed formulation which leads to predictions in terms of the pion-nucleon scattering phase shifts and a set of Migdal parameters describing important short range correlation effects. We do not observe any significant softening of pion modes if we insist on reasonable isobar resonance properties but predict a considerable broadening of the N(1440) and N(1520) resonances in nuclear matter. (orig.)Available from TIB Hannover: RO 801(03-18) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Mikrosystemtechnik zum Einsatz in der minimalinvasiven neurochirurgischen Operationstechnik (MINOP). Verbundprojekt 1993 - 1996 Abschlussbericht

SIGLEAvailable from TIB Hannover: RR 3532(50) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman