Mixed Tournaments, Common Shocks, and Disincentives: An Experimental Study

Experimental economics is used to investigate two important hypotheses proposed in the economics literature on tournaments. Specifically, we test for a hypothesized “disincentives effect” which can occur in tournaments with mixed ability agents. We also test the well known hypothesis that, when common shocks are an important source of risk, tournaments can filter out this common shock and reduce earnings risk to workers. We find that disincentive effects arose in our tournament experiments, although these effects are not as strong as we predicted in our theoretical model and simulations. We also find that tournaments can be very effective at reducing earnings variation when common shocks are important. Taken together, these results suggest that the benefits of risk reduction from eliminating common shocks might outweigh the disincentive effects arising from mixed tournaments. We also find that the difference in average earnings between low and high ability agents is greater under tournaments than under absolute performance contracts.mixed tournaments; incentives; relative performance contracts; experimental economics

Investigating the Role of Collegiate Athletic Director in Addressing Head Trauma Prevention

Within collegiate athletics, there is a growing interest in the management of head trauma incidents. This qualitative study was designed to answer two research questions: (1) What is the role of athletic directors in the management of head trauma prevention? (2) What are the major concerns of athletic directors regarding head trauma prevention and what should happen in the future? Findings from the research questions revealed three themes: (a) Indirect mention of head trauma prevention in athletic director job description, (b) athletic director delegation to medical professionals, and (c) athletic directors want more research and education on head trauma prevention. Although new in scholarly research, head trauma prevention should continue to be a priority for collegiate athletic directors

Real versus complex K-theory using Kasparov's bivariant KK-theory

In this paper, we use the KK-theory of Kasparov to prove exactness of sequences relating the K-theory of a real C^*-algebra and of its complexification (generalizing results of Boersema). We use this to relate the real version of the Baum-Connes conjecture for a discrete group to its complex counterpart. In particular, the complex Baum-Connes assembly map is an isomorphism if and only if the real one is, thus reproving a result of Baum and Karoubi. After inverting 2, the same is true for the injectivity or surjectivity part alone.Comment: Published by Algebraic and Geometric Topology at http://www.maths.warwick.ac.uk/agt/AGTVol4/agt-4-18.abs.htm

Preliminary investigation of the effects of long-term dietary intake of genistein and daidzein on hepatic histopathology and biochemistry in domestic cats (Felis catus)

Dietary isoflavones have been hypothesised to play a role in hepatic veno-occlusive disease in captive exotic felids, although empirical evidence is lacking. This study aimed to investigate the effect of long-term (>1 year) dietary genistein and daidzein exposure on the hepatic biochemistry and histology of domestic cats. Individual cats were assessed for hepatic enzyme and bile acid production before and after the removal of isoflavones from their diet in the treatment group (n=4), and at the same times in unexposed control animals (n=7). No significant differences were detectable in hepatic biochemistry between treatment and control groups, and all serum values were within the normal reference ranges for domestic cats. Additionally, treatment animals demonstrated slightly greater areas of fibrosis surrounding hepatic venules than control animals, but this difference was not statistically significant. On the basis of the results presented, dietary isoflavones, at the current dose and duration of exposure do not appear to modulate hepatic enzyme production or histological parameters

Preliminary investigation of the influence of long-term dietary isoflavone intake on reproductive tract histology and sex steroid receptor expression in female domestic cats (Felis catus)

Genistein and daidzein are isoflavones which are reported to influence the reproductive system in a variety of mammalian species. This pilot study aimed to determine if dietary isoflavones could potentially influence reproductive tract histology or morphology in domestic cats, when consumed during the postnatal development period. Cats were maintained on either treatment (150 µg/g DM genistein and 150 µg/g DM daidzein, n=4) or control (isoflavone free, n=8) diets from weaning, up to 414 (±17.2) days post-weaning. Reproductive tissues were collected during routine ovario-hysterectomy and examined for histology and sex steroid receptor expression. Findings indicate that these dietary isoflavones influenced the expression of oestrogen receptor α (ERα) and oestrogen receptor β (ERβ), and progesterone receptor in feline reproductive tissues. One cat in the treatment group developed suppurative endometritis, but no evidence of uterotrophic or histological changes were found in any other cats. The potential to alter expression of hormone receptors in the reproductive tract of domestic cats exposed to genistein and daidzein warrants further investigation

Mixed Tournaments, Common Shocks, and Disincentives: An Experimental Study

Two well-known hypotheses from the literature on tournaments are that (1) tournaments can filter out common shocks thereby reducing agents risk exposure; and (2) disincentive effects can arise when a tournament scheme is administered on a group of mixed ability agents. While handicapping and/or the creation of homogeneous groups have been suggested as mechanisms for mitigating disincentive effects, it is often impractical to use handicapping schemes and nearly impossible to create a completely homogeneous labor force. Hence, contract administrators who intend to use tournaments to elicit effort must be able to assess the positive effects of tournaments (eliminate common shocks) against the negative effects (disincentive effects). Using economic experiments, we find evidence of disincentive effects under tournaments, although these effects are not as strong as predicted. Moreover, tournaments can be effective at reducing earnings variability when common shocks are important. These results suggest that the benefits of risk reduction from eliminating common shocks might outweigh the disincentive effects arising from mixed tournaments.mixed tournaments, incentives, relative performance contracts, experimental economics, Research Methods/ Statistical Methods, C91 D01, D81, D82, D86,

Autonomous rendezvous and capture development infrastructure

In the development of the technology for autonomous rendezvous and docking, key infrastructure capabilities must be used for effective and economical development. This involves facility capabilities, both equipment and personnel, to devise, develop, qualify, and integrate ARD elements and subsystems into flight programs. One effective way of reducing technical risks in developing ARD technology is the use of the ultimate test facility, using a Shuttle-based reusable free-flying testbed to perform a Technology Demonstration Test Flight which can be structured to include a variety of additional sensors, control schemes, and operational approaches. This conceptual testbed and flight demonstration will be used to illustrate how technologies and facilities at MSFC can be used to develop and prove an ARD system

Short-range/Long-range Integrated Target (SLIT) for Video Guidance Sensor Rendezvous and Docking

A laser target reflector assembly for mounting upon spacecraft having a long-range reflector array formed from a plurality of unfiltered light reflectors embedded in an array pattern upon a hemispherical reflector disposed upon a mounting plate. The reflector assembly also includes a short-range reflector array positioned upon the mounting body proximate to the long-range reflector array. The short-range reflector array includes three filtered light reflectors positioned upon extensions from the mounting body. The three filtered light reflectors retro-reflect substantially all incident light rays that are transmissive by their monochromatic filters and received by the three filtered light reflectors. In one embodiment the short-range reflector array is embedded within the hemispherical reflector

Development of non-dissipative numerical schemes for computational aeroacoustics

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76586/1/AIAA-1993-3382-851.pd