Labor contracts and business cycles

This paper investigates tbe c1aim, often put forth by Real Business Cycle proponents (e.g Prescott (1986», that the poor performance of their models in matching real world aggregate labor market behavior are due to tbe fact that observed real wage payments do not correspond to the actual marginal productivity of labor but contain an insurance component which cannot be accounted for by the Walrasian pricing mecbanism. To test this idea we dispense with tbe Walrasian description of the labor market and introduce contractual arrangements between employees and employers. Assuming that the former are prevented from accessing capital markets and are more risk averse than the latter we use tbe theory optimal contracts to derive an equilibrium relation between aggregate states of the economy and wage-Labor outcomes. This contractual arrangement is then embedded into a standard one-sector, stochastic neoclassical growth model in order to look at the business cycle implications of the contractual hypotbesis. The resulting dynamic equilibrium relations are then parameterized and studied by means of standard numerical approximation techniques. The quantitative properties of our model appear to be somewhat encouraging. We have examined different contractual environments and in all circumstances the contracts-based equilibrium performs better than standard ones witb regard to the labor-market variables and at least as well witb regard to the otber aggregate macroeconomic variables. The present paper reports only the simulation results relative to what we consider tbe most empirically relevant cases. More results are available from the authors

Labor contracts and business cycles.

This paper investigates tbe c1aim, often put forth by Real Business Cycle proponents (e.g Prescott (1986», that the poor performance of their models in matching real world aggregate labor market behavior are due to tbe fact that observed real wage payments do not correspond to the actual marginal productivity of labor but contain an insurance component which cannot be accounted for by the Walrasian pricing mecbanism. To test this idea we dispense with tbe Walrasian description of the labor market and introduce contractual arrangements between employees and employers. Assuming that the former are prevented from accessing capital markets and are more risk averse than the latter we use tbe theory optimal contracts to derive an equilibrium relation between aggregate states of the economy and wage-Labor outcomes. This contractual arrangement is then embedded into a standard one-sector, stochastic neoclassical growth model in order to look at the business cycle implications of the contractual hypotbesis. The resulting dynamic equilibrium relations are then parameterized and studied by means of standard numerical approximation techniques. The quantitative properties of our model appear to be somewhat encouraging. We have examined different contractual environments and in all circumstances the contracts-based equilibrium performs better than standard ones witb regard to the labor-market variables and at least as well witb regard to the otber aggregate macroeconomic variables. The present paper reports only the simulation results relative to what we consider tbe most empirically relevant cases. More results are available from the authors.

Extending Phenomenological Crystal-Field Methods to C1C_1 Point-Group Symmetry: Characterization of the Optically-Excited Hyperfine Structure of 167^{167}Er3+^{3+}:Y2_2SiO5_5

We show that crystal-field calculations for $C_1$ point-group symmetry are possible, and that such calculations can be performed with sufficient accuracy to have substantial utility for rare-earth based quantum information applications. In particular, we perform crystal-field fitting for a C$_1$-symmetry site in $^{167}$Er$^{3+}$:Y$_2$SiO$_5$. The calculation simultaneously includes site-selective spectroscopic data up to 20,000 cm$^{-1}$, rotational Zeeman data, and ground- and excited-state hyperfine structure determined from high-resolution Raman-heterodyne spectroscopy on the 1.5 $\mu$m telecom transition. We achieve an agreement of better than 50 MHz for assigned hyperfine transitions. The success of this analysis opens the possibility of systematically evaluating the coherence properties, as well as transition energies and intensities, of any rare-earth ion doped into Y$_2$SiO$_5$ .Comment: 6 pages, plus 5 pages in supplementary information, 4 figures tota

Exosomes containing HIV protein Nef reorganize lipid rafts potentiating inflammatory response in bystander cells.

HIV infection has a profound effect on "bystander" cells causing metabolic co-morbidities. This may be mediated by exosomes secreted by HIV-infected cells and containing viral factors. Here we show that exosomes containing HIV-1 protein Nef (exNef) are rapidly taken up by macrophages releasing Nef into the cell interior. This caused down-regulation of ABCA1, reduction of cholesterol efflux and sharp elevation of the abundance of lipid rafts through reduced activation of small GTPase Cdc42 and decreased actin polymerization. Changes in rafts led to re-localization of TLR4 and TREM-1 to rafts, phosphorylation of ERK1/2, activation of NLRP3 inflammasome, and increased secretion of pro-inflammatory cytokines. The effects of exNef on lipid rafts and on inflammation were reversed by overexpression of a constitutively active mutant of Cdc42. Similar effects were observed in macrophages treated with exosomes produced by HIV-infected cells or isolated from plasma of HIV-infected subjects, but not with exosomes from cells and subjects infected with ΔNef-HIV or uninfected subjects. Mice injected with exNef exhibited monocytosis, reduced ABCA1 in macrophages, increased raft abundance in monocytes and augmented inflammation. Thus, Nef-containing exosomes potentiated pro-inflammatory response by inducing changes in cholesterol metabolism and reorganizing lipid rafts. These mechanisms may contribute to HIV-associated metabolic co-morbidities

Making the most of the European Fiscal Board

Nach den zahlreichen fiskalpolitischen Reformen in der Eurozone seit 2011 wurde im Jahr 2016 eine weitere wichtige Neuerung eingeführt: die Gründung des Europäischen Finanzausschusses (EFB) sowie die Auswahl und Ernennung seiner fünf Mitglieder. Der Fiskalausschuss war einer der Vorschläge, die im Bericht der fünf Präsidenten im Juni 2015 (Juncker et al., 2015) mit dem Ziel der Schaffung einer "Fiskalunion" vorgebracht wurden. Es ist außerdem das einzige Element des Berichts, das innerhalb von kürzester Zeit umgesetzt wurde. Der Vorschlag über die Einrichtung einer solchen Institution wurde im Oktober 2015 von der Europäischen Kommission eingereicht. Bereits im Oktober 2016 nahm der Fiskalausschuss kurze Zeit nach Ernennung seiner Mitglieder seine Arbeit auf

Chiral phase transition and Anderson localization in the Instanton Liquid Model for QCD

We study the spectrum and eigenmodes of the QCD Dirac operator in a gauge background given by an Instanton Liquid Model (ILM) at temperatures around the chiral phase transition. Generically we find the Dirac eigenvectors become more localized as the temperature is increased. At the chiral phase transition, both the low lying eigenmodes and the spectrum of the QCD Dirac operator undergo a transition to localization similar to the one observed in a disordered conductor. This suggests that Anderson localization is the fundamental mechanism driving the chiral phase transition. We also find an additional temperature dependent mobility edge (separating delocalized from localized eigenstates) in the bulk of the spectrum which moves toward lower eigenvalues as the temperature is increased. In both regions, the origin and the bulk, the transition to localization exhibits features of a 3D Anderson transition including multifractal eigenstates and spectral properties that are well described by critical statistics. Similar results are obtained in both the quenched and the unquenched case though the critical temperature in the unquenched case is lower. Finally we argue that our findings are not in principle restricted to the ILM approximation and may also be found in lattice simulations.Comment: 14 pages, 13 figure

Fitter, Happier, More Productive? The Normative Ontology of Fitness Trackers

Fitness trackers promise a longer and better life for the people who engage with them. What is forgotten in their analysis for HCI, though, is how they re-conceptualise the very notion of what constitutes a 'step'. We discuss everyday edge cases illustrating how fitness trackers fail to address goals and ideals of people using them. They merely re-affirm the fitness of already fit people and can have an adversarial effect on others. For future designers, we offer strategies to become aware of their own biases and provide implications for designers potentially leading to more non-normative and diverse designs of trackers