66 research outputs found
Transmission of Monetary Policy with Heterogeneity in Household Portfolios
This paper assesses the importance of heterogeneity in household portfolios for the transmission of monetary policy in a New Keynesian business cycle model with uninsurable income risk and assets with different liquidity. In this environment, monetary transmission works through investment, but redistribution lowers the elasticity of investment via two channels: (i) heterogeneity in marginal propensities to invest, and (ii) time variation in the liquidity premium. Monetary contractions redistribute to wealthy households who have high propensities to invest and a low marginal value of liquidity, thereby stabilizing investment. I provide empirical evidence for countercyclical liquidity premia and heterogeneity in household portfolio responses
Comment on “The Household Channel of Monetary Policy in the Euro Area: A Back of the Envelope Calculation”
Solving discrete time heterogeneous agent models with aggregate risk and many idiosyncratic states by perturbation
This paper describes a method for solving heterogeneous agent models with aggregate risk and many idiosyncratic states formulated in discrete time. It extends the method proposed by Reiter (2009) and complements recent work by Ahn, Kaplan, Moll, Winberry, and Wolf (2017) on how to solve such models in continuous time. We suggest first solving for the stationary equilibrium of the model without aggregate risk. We then write the functionals that describe the dynamic equilibrium as sparse expansions around their stationary equilibrium counterparts. Finally, we use the perturbation method of Schmitt‐Grohé and Uribe (2004) to approximate the aggregate dynamics of the model
Three-dimensional modelling of edge-on disk galaxies
We present detailed three-dimensional modelling of the stellar luminosity
distribution for the disks of 31 relatively nearby (<= 110 Mpc) edge-on spiral
galaxies. In contrast to most of the standard methods available in the
literature we take into account the full three-dimensional information of the
disk. We minimize the difference between the observed 2D-image and an image of
our 3D-disk model integrated along the line of sight. Thereby we specify the
inclination, the fitting function for the z-distribution of the disk, and the
best values for the structural parameters such as scalelength, scaleheight,
central surface brightness, and a disk cut-off radius. From a comparison of two
independently developed methods we conclude, that the discrepancies e.g. for
the scaleheights and scalelengths are of the order of ~10%. These differences
are not due to the individual method itself, but rather to the selected fitting
region, which masks the bulge component, the dust lane, or present foreground
stars. Other serious limitations are small but appreciable intrinsic deviations
of real disks compared to the simple input model. In this paper we describe the
methods and present contour plots as well as radial profiles for all galaxies
without previously published surface photometry. Resulting parameters are given
for the complete sample.Comment: LaTeX, 25 pages, 28 figures higher quality figures available at
http://www.astro.ruhr-uni-bochum.de/astro/publications/pub2000.htm
Outer edges of face-on spiral galaxies
We present deep optical imaging of three face-on disk galaxies together with
a detailed description of the reduction and calibration methods used, in order
to measure the intrinsic shape of their outer stellar edges. Whereas it is now
well accepted that disks of spiral galaxies are not infinite exponential beyond
galactocentric distances of about 3-5 radial scalelengths, the genuine
structure of the truncation region is not yet well known. Our data
quantitatively establish a smooth truncation behaviour of the radial surface
brightness profiles and is best described by a two-slope model, characterised
by an inner and outer exponential scalelength separated at a relatively well
defined break radius. This result disagrees with the frequently assumed sharply
truncated nature of the radial surface brightness profiles and implies the
presence of stars and even star-formation beyond the break radius. In addition,
we do not find a strong influence of a nearby companion on the ratio of the
break radius to the radial scalelength. Our results denote new observational
constraints for the search of the physical explanation for these smooth disk
truncations.Comment: LaTeX, 10 pages, 17 figures, accepted to be published in A&A, minor
changes to the quality of figure
Precautionary Savings, Illiquid Assets, and the Aggregate Consequences of Shocks to Household Income Risk
Households face large income uncertainty that varies substantially over the business cycle. We examine the macroeconomic consequences of these variations in a model with incomplete markets, liquid and illiquid assets, and a nominal rigidity. Heightened uncertainty depresses aggregate demand as households respond by hoarding liquid “paper” assets for precautionary motives, thereby reducing both illiquid physical investment and consumption demand. We document the empirical response of portfolio liquidity and aggregate activity to surprise changes in idiosyncratic income uncertainty and find both to be quantitatively in line with our model. The welfare consequences of uncertainty shocks and of the policy response thereto depend crucially on a household's asset positio
Measurements of the branching fractions for decays at Belle II
This paper reports a study of decays using
fb of data collected during 2019--2020 by the Belle II experiment at the
SuperKEKB asymmetric-energy collider, corresponding to events. We find , ,
, and signal events in the decay modes , ,
, and , respectively. The uncertainties quoted for the
signal yield are statistical only. We report the branching fractions of these
decays: where the first
uncertainty is statistical, and the second is systematic. The results are
consistent with world-average values
Angular analysis of decays reconstructed in 2019, 2020, and 2021 Belle II data
We report on a Belle II measurement of the branching fraction
(), longitudinal polarization fraction (), and CP asymmetry
() of decays. We reconstruct decays in a
sample of SuperKEKB electron-positron collisions collected by the Belle II
experiment in 2019, 2020, and 2021 at the (4S) resonance and
corresponding to 190 fb of integrated luminosity. We fit the
distributions of the difference between expected and observed candidate
energy, continuum-suppression discriminant, dipion masses, and decay angles of
the selected samples, to determine a signal yield of events. The
signal yields are corrected for efficiencies determined from simulation and
control data samples to obtain $\mathcal{B}(B^+ \to \rho^+\rho^0) = [23.2^{+\
2.2}_{-\ 2.1} (\rm stat) \pm 2.7 (\rm syst)]\times 10^{-6}f_L = 0.943 ^{+\
0.035}_{-\ 0.033} (\rm stat)\pm 0.027(\rm syst)\mathcal{A}_{CP}=-0.069
\pm 0.068(\rm stat) \pm 0.060 (\rm syst)\mathcal{A}_{CP}B^+\to
\rho^+\rho^0$ decays reported by Belle II
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