Heterogeneity in an RBC Model with Durable Goods and Energy

Bergmann P. Heterogeneity in an RBC Model with Durable Goods and Energy. Universität Bielefeld Working Papers in Economics and Management. Vol 13-2019. Bielefeld: Bielefeld University, Department of Business Administration and Economics; 2019.This paper investigates the effects of total factor productivity and energy price shocks in a real business cycle (RBC) model with heterogeneous agents. It extends standard RBC models by including the distinction between durable goods and non-durable goods but also including energy in production of non-durable goods. Furthermore, we combine two sources of heterogeneity using idiosyncratic shocks in labor supply and limited asset market participation by a fixed proportion of agents. We study to what degree the empirically observed inequality in income and wealth can be explained by the provided framework. The model can predict the evolution of inequality in income and wealth, unlike traditional homogeneous macroeconomic models with a representative agent. We show that the distinction between nondurable and durable goods leads to a significant improvement in predicting most of the moments close to the one in observational data from Germany. Furthermore, we find that energy price shocks lead to decreasing inequalities, with respect to both income and wealth. In a brief policy analysis, we give an outlook about the effects of redistribution of income between classes of agents

Behavioral diversity and biomechanical determinants of the outcome of a fish predator–prey interaction

Predator–prey interactions are ubiquitous and under strong selection because of the consequences experienced by both predator and prey if they lose the interaction. Biomechanics and behavior play important roles in the outcome of these interactions, but many studies focus on the prey, restrict the range of behaviors considered, and the role of prey boldness in the outcome is not understood. We used high-speed video to test for effects of multiple measures of performance and kinematics of both the predator and prey, and boldness of prey on the outcome of interactions between Pike Cichlids (Crenicichla sp.) and Guppies (Poecilia reticulata). We found high variation in the behaviors employed during the predator–prey interactions, including in suction versus raptorial feeding, strike accuracy, and guppy responsiveness. We also found that predators moving relatively slower and prey moving relatively faster were more successful at consuming the prey and evading the predator, respectively. Prey that reacted farther from the predator was more likely to escape predation, but boldness of the prey did not affect the interaction. Our work suggests that a high level of variation in predator–prey interactions is widespread, even when strike and escape behaviors are stereotyped. We also showed that what both the predator and the prey do during an interaction are important in determining the outcome. © 2023 The Authors. Journal of Zoology published by John Wiley & Sons Ltd on behalf of Zoological Society of London

Oil Price Shocks and GDP Growth: Do Energy Shares Amplify Causal Effects?

Bergmann P. Oil Price Shocks and GDP Growth: Do Energy Shares Amplify Causal Effects?. Working Papers in Economics and Management. Vol 10-2017. Bielefeld: Bielefeld University, Department of Business Administration and Economics; 2017.The paper estimates the effect of oil price uctuations on GDP growth, using linear and nonlinear VAR models with data from 12 countries. It reports strong significance for the existence of non-linear moderator effects caused by a decline in the oil-to-energy share, which weakens the causal effect of oil prices on economic growth. A consideration of the relationship of oil prices and GDP over 44 years confirms the exclusion of symmetry of previous studies. Moreover, the paper indicates that the effect of negative oil price movements is causal for more countries than has been suggested so far

Durable Goods and Energy in RBC. An Endogenous Multisectoral Model

Bergmann P. Durable Goods and Energy in RBC. An Endogenous Multisectoral Model. Universität Bielefeld Working Papers in Economics and Management. Vol 08-2018. Bielefeld: Bielefeld University, Department of Business Administration and Economics; 2018.We have constructed a RBC model where energy is endogenously minded. It is generated within the model from fossil intermediate and renewable energy resources and consumed by final good production and households. Furthermore, households can invest in a durable good to avoid exaggerated disruptive investment dynamics. By estimating the model using Bayesian techniques and with data from the German economy, we find a complementary relationship between durable goods and energy consumption in the household sector as well as between physical capital and energy consumption in the final good sector. Furthermore, a TFP shock in the (final and intermediate) energy sectors has a larger effect on durable good purchases than on capital investments in the final good production. Nevertheless, even with endogenous price determination of energy, TFP in final good production is still the major contributor to business cycle formation in a classical framework. In an extension, we show that despite of allowing the replenish the constrained fossil stock, the dynamic responds of the variables do not deviate from the baseline model

Essays on Energy in Macroeconomic Models

Bergmann P. Essays on Energy in Macroeconomic Models. Bielefeld: Universität Bielefeld; 2019

Electronics and Sensor Subsystem Design for Daedalus 2 on REXUS 29: An Autorotation Probe for Sub-Orbital Re-Entry

The Daedalus 2 mission aboard REXUS 29 is a technology demonstrator for an alternative descent mechanism for very high altitude drops based on auto-rotation. It consists of two probes that are ejected from a sounding rocket at an altitude of about 80 km and decelerate to a soft landing using only a passive rotor with pitch control. This type of autonomous, scientific experiment poses great challenges upon the electronics subsystem, which include mechanical stress, power system reliability, sensor redundancy, subsystem communication, and development procedures. Based on the data gathered in Daedalus 1 multiple new approaches were developed to fulfill these requirements, such as redundant communication links, mechanical decoupling of PCBs and fault-tolerant power source selection.Comment: 8 pages, 10 figure

Flavor Changing Supersymmetry Interactions in a Supernova

We consider for the first time R-parity violating interactions of the Minimal Standard Supersymmetric Model involving neutrinos and quarks (``flavor changing neutral currents'', FCNC's) in the infall stage of stellar collapse. Our considerations extend to other kinds of flavor changing neutrino reactions as well. We examine non-forward neutrino scattering processes on heavy nuclei and free nucleons in the supernova core. This investigation has led to four principal original discoveries/products: (1) first calculation of neutrino flavor changing cross sections for spin one half (e.g. free nucleon) and spin zero nuclear targets; (2) discovery of nuclear mass number squared (A squared) coherent amplification of neutrino-quark FCNC's; (3) analysis of FCNC-induced alteration of electron capture and weak/nuclear equilibrium in the collapsing core; and (4) generalization of the calculated cross sections (mentioned in 1) for the case of hot heavy nuclei to be used in collapse/supernova and neutrino transport simulations. The scattering processes that we consider allow electron neutrinos to change flavor during core collapse, thereby opening holes in the electron neutrino sea, which allows electron capture to proceed and results in a lower core electron fraction. A lower electron fraction implies a lower homologous core mass, a lower shock energy, and a greater nuclear photo-disintegration burden for the shock. In addition, unlike the standard supernova model, the core now could have net muon and/or tau lepton numbers. These effects could be significant even for supersymmetric couplings below current experimental bounds.Comment: 22 pages, 7 figures, typos corrected, abstract modifided, minor additions to conten

Geochemical evidence of the seasonality, affinity and pigmenation of Solenopora jurassica

Solenopora jurassica is a fossil calcareous alga that functioned as an important reef-building organism during the Palaeozoic. It is of significant palaeobiological interest due to its distinctive but poorly understood pink and white banding. Though widely accepted as an alga there is still debate over its taxonomic affinity, with recent work arguing that it should be reclassified as a chaetetid sponge. The banding is thought to be seasonal, but there is no conclusive evidence for this. Other recent work has, however demonstrated the presence of a unique organic boron-containing pink/red pigment in the pink bands of S. jurassica. We present new geochemical evidence concerning the seasonality and pigmentation of S. jurassica. Seasonal growth cycles are demonstrated by X-ray radiography, which shows differences in calcite density, and by varying δ13C composition of the bands. Temperature variation in the bands is difficult to constrain accurately due to conflicting patterns arising from Mg/Ca molar ratios and δ18O data. Fluctuating chlorine levels indicate increased salinity in the white bands, when combined with the isotope data this suggests more suggestive of marine conditions during formation of the white band and a greater freshwater component (lower chlorinity) during pink band precipitation (δ18O). Increased photosynthesis is inferred within the pink bands in comparison to the white, based on δ13C. Pyrolysis Gas Chromatography Mass Spectrometry (Py-GCMS) and Fourier Transform Infrared Spectroscopy (FTIR) show the presence of tetramethyl pyrrole, protein moieties and carboxylic acid groups, suggestive of the presence of the red algal pigment phycoerythrin. This is consistent with the pink colour of S. jurassica. As phycoerythrin is only known to occur in algae and cyanobacteria, and no biomarker evidence of bacteria or sponges was detected we conclude S. jurassica is most likely an alga. Pigment analysis may be a reliable classification method for fossil algae

One-year outcomes after transcatheter insertion of an interatrial shunt device for the management of heart failure with preserved ejection fraction

Background—Heart failure with preserved ejection fraction has a complex pathophysiology and remains a therapeutic challenge. Elevated left atrial pressure, particularly during exercise, is a key contributor to morbidity and mortality. Preliminary analyses have demonstrated that a novel interatrial septal shunt device that allows shunting to reduce the left atrial pressure provides clinical and hemodynamic benefit at 6 months. Given the chronicity of heart failure with preserved ejection fraction, evidence of longer-term benefit is required. Methods and Results—Patients (n=64) with left ventricular ejection fraction ≥40%, New York Heart Association class II–IV, elevated pulmonary capillary wedge pressure (≥15 mm Hg at rest or ≥25 mm Hg during supine bicycle exercise) participated in the open-label study of the interatrial septal shunt device. One year after interatrial septal shunt device implantation, there were sustained improvements in New York Heart Association class (P<0.001), quality of life (Minnesota Living with Heart Failure score, P<0.001), and 6-minute walk distance (P<0.01). Echocardiography showed a small, stable reduction in left ventricular end-diastolic volume index (P<0.001), with a concomitant small stable increase in the right ventricular end-diastolic volume index (P<0.001). Invasive hemodynamic studies performed in a subset of patients demonstrated a sustained reduction in the workload corrected exercise pulmonary capillary wedge pressure (P<0.01). Survival at 1 year was 95%, and there was no evidence of device-related complications. Conclusions—These results provide evidence of safety and sustained clinical benefit in heart failure with preserved ejection fraction patients 1 year after interatrial septal shunt device implantation. Randomized, blinded studies are underway to confirm these observations