Idiosyncratic Risk and Aggregate Employment Dynamics

This paper studies how producers' idiosyncratic risks affect an industry's aggregate dynamics in an environment where certainty equivalence fails. In the model, producers can place workers in two types of jobs, organized and temporary. Workers are less productive in temporary jobs, but creating an organized job requires an irreversible investment of managerial resources. Increasing productivity risk raises the value of an unexercised option to create an organized job. Losing this option is one cost of immediate organized job creation, so an increase in its value induces substitution towards cheaper temporary jobs. Because they are costless to create and destroy, a producer using temporary jobs can be more flexible, responding more to both idiosyncratic and aggregate shocks. If all of an industry's producers adapt to heightened idiosyncratic risk in this way, the industry as a whole can respond more to a given aggregate shock. This insight is used to better understand the observation from the U.S. manufacturing sector that groups of plants displaying high idiosyncratic variability also have large aggregate fluctuations.

Idiosyncratic risk and aggregate employment dynamics

This paper studies how producers’ idiosyncratic risks affect an industry’s aggregate dynamics in an environment where certainty equivalence fails. In the model, producers can place workers in two types of jobs, organized and temporary. Workers are less productive in temporary jobs, but creating an organized job requires an irreversible investment of managerial resources. Increasing productivity risk raises the value of an unexercised option to create an organized job. Losing this option is one cost of immediate organized job creation, so an increase in its value induces substitution towards cheaper temporary jobs. Because they are costless to create and destroy, a producer using temporary jobs can be more flexible, responding more to both idiosyncratic and aggregate shocks. If all of an industry’s producers adapt to heightened idiosyncratic risk in this way, the industry as a whole can respond more to a given aggregate shock. This insight is used to better understand the observation from the U.S. manufacturing sector that groups of plants displaying high idiosyncratic variability also have large aggregate fluctuations.Employment (Economic theory) ; Temporary employees

Understanding aggregate job flows

The authors describe how evidence on aggregate job flows challenges standard business cycle theory and discuss recent developments in business cycle theory aimed at accounting for the evidence.Business cycles ; Employment (Economic theory) ; Labor market

Aggregate Employment Fluctuations with Microeconomic Asymmetries

We provide a simple explanation for the observation that the variance of job destruction is greater than the variance of job creation: job creation is costlier at the margin than job destruction. As Caballero [2] has argued, asymmetric employment adjustment costs at the establishment level need not imply asymmetric volatility of aggregate job flows. We construct an equilibrium model in which (S,s)-type employment policies respond endogenously to aggregate shocks. The microeconomic asymmetries in the model can dampen the response of total job creation to an aggregate shock and cause it to be less volatile than total job destruction. This is so even though aggregate shocks are symmetrically distributed.

A wireless method for monitoring medication compliance

There are many devices on the market to help remind patients to take their pills, but most require observation by a caregiver to assure medication compliance. This project demonstrates three modes to detect pill removal from a pillbox: a switch under the pills, a reflective type photointerrupter and a transmissive electric eye photosensor. Each mode exhibited blind spots or other failures to detect pill presence, but by combining modes with complementary characteristics, the accuracy of pill detection is greatly increased. Two methods of caregiver notification are demonstrated: text messages transmitted via an attached cellular phone, or the status is collected by a PC which provides an audit trail and daily notification if no pills were taken

In Response: The Biological Basis and Treatment of Bulimia

The recent papers in the Jefferson J ournal of Psychiatry by Drs. Levin ( Bulimia as a Masturbatory Equivalent, July, 1985) and Wilson ( A Discussion of \u27Bulimia as a Masturbatory Equivalent\u27, Winter, 1986) contain a number of theories and recommendations about the etiology and treatment of bulimia which should be addressed. In large measure, both papers present a dynamic view of this disorder. However, psychodynamic formulations are but one of many theories put forward to explain this disorder. Other theories of etiology include notions that bulimia arises from cultural factors and an increased attention to body image, from disorders with in the family as a whole, or from assorted behavioral factors which somehow reinforce binge-eating and purging

Measurements of noise in Josephson-effect mixers

We present new heterodyne receiver results obtained at 100 GHz using resistively-shunted Nb and NbN tunnel junctions. In addition, we have carried out accurate measurements of the available noise power of these devices at the L-band (1.5 GHz) IF frequency. Both the heterodyne and the output noise measurements show that the noise of these devices can be a factor of five or more higher than that predicted by the simple current-biased RSJ model. The noise approaches the appropriate thermal or thermal and shot noise limits for bias voltages where the nonlinearity is not strong (i.e., V>ICRN), but as expected from the RSJ model, can be significantly higher at the low voltages where the mixers are typically biased. The bias voltage dependence of the noise shows structure which is associated with resonances in the RF embedding circuit. Surprisingly, we find that changes in the high-frequency (100 GHz) impedance presented to the junction can dramatically affect the magnitude and voltage dependence of the low-frequency (1.5 GHz) noise. This emphasizes the necessity of very closely matching the junction to free space over a wide frequency range

Characterization of low-noise quasi-optical SIS mixers for the submillimeter band

We report on the development of low-noise quasi-optical SIS mixers for the frequency range 400-850 GHz. The mixers utilize twin-slot antennas, two-junction tuning circuits, and Nb-trilayer junctions. Fourier-transform spectrometry has been used to verify that the frequency response of the devices is well predicted by computer simulations. The 400-850 GHz frequency band can be covered with four separate fixed-tuned mixers. We measure uncorrected double-sideband receiver noise temperatures around 5hν/kB to 700 GHz, and better than 540 K at 808 GHz. These results are among the best reported to date for broadband heterodyne receivers

Organizational flexibility and employment dynamics at young and old plants

There are significant differences in the dynamics of employment over the business cycle between young and old manufacturing plants. Young plants are more sensitive to aggregate disturbances, and they respond to them along different margins. We interpret these differences as reflecting greater organizational flexibility at young plants due to the changing nature of a plant's environment as it ages. In the presence of aggregate uncertainty, differences between young and old plants' organizational flexibility allows the model to reproduce their distinct cyclical characteristics. Previous empirical studies show that small firms generally respond by more to aggregate shocks than do large firms. To the extent that small firms tend to operate young plants, our analysis suggests an alternative to conventional explanations of this evidence which appeal to imperfections in credit markets.Employment (Economic theory) ; Industries ; Business cycles

Magnetic Switching of Phase-Slip Dissipation in NbSe2 Nanobelts

The stability of the superconducting dissipationless and resistive states in single-crystalline NbSe2 nanobelts is characterized by transport measurements in an external magnetic field (H). Current-driven electrical measurements show voltage steps, indicating the nucleation of phase-slip structures. Well below the critical temperature, the position of the voltage steps exhibits a sharp, periodic dependence as a function of H. This phenomenon is discussed in the context of two possible mechanisms: the interference of the order parameter and the periodic rearrangement of the vortex lattice within the nanobelt.Comment: 4 figure