Are flexible contracts bad for workers? Evidence from job satisfaction data

If workers can choose between permanent and flexible contracts, compensating wage differentials should arise to equalize on-the-job utility in the two types of contracts. Estimating job satisfaction using the British Household Panel Survey shows that agency and casual contracts are associated with routinely lower satisfaction. This results because the low job satisfaction associated with less job security is not offset by higher compensation or other job characteristics. Job security is sufficiently important that holding constant this one facet of satisfaction eliminates the overall gap in job satisfaction between flexible and permanent contracts

Three-dimensional cometary dust coma modelling in the collisionless regime: strengths and weaknesses

Inverse coma and tail modelling of comets based on the method developed by Finson & Probstein is commonly used to analyse cometary coma images. Models of this type often contain a large number of assumptions that may not be constrained unless wide temporal or spectral coverage is available and the comets are bright and at relatively small geocentric distance. They are used to predict physical parameters, such as the mass distribution of the dust, but rarely give assessments of the accuracy of the estimate. A three-dimensional cometary dust coma model in the collisionless regime has been developed to allow the effectiveness of such models to constrain dust coma properties to be tested. The model is capable of simulating the coma morphology for the following input parameters: the comet nucleus shape, size, rotation, emission function (including active fraction and jets), grain velocity distribution (and dispersion), size distribution, dust production rate, grain material and light scattering from the cometary dust. Characterization of the model demonstrates that the mass distribution cannot be well constrained as is often assumed; the cumulative mass distribution index ? can only be constrained to within ±0.15. The model is highly sensitive to the input grain terminal velocity distribution so model input can be tested with a large degree of confidence. Complex secondary parameters such as jets, rotation and grain composition all have an effect on the structure of the coma in similar ways, so unique solutions for these parameters cannot be derived from a single optical image alone. Multiple images at a variety of geometries close in time can help constrain these effects. The model has been applied to photometric observations of comets 126P/IRAS and 46P/Wirtanen to constrain a number of physical properties including the dust production rate and mass distribution index. The derived dust production rate (Qdust) for 46P/Wirtanen was 3+7/1.5 kg s1 at a pre-perihelion heliocentric distance of 1.8 au, and for P/IRAS was 50+100/20 kg s1 at a pre-perihelion heliocentric distance of 1.7 au; both comets exhibited a mass distribution index ? = 0.8 ± 0.15

Profit Sharing and the Quality of Relations with the Boss

Profit sharing generates conflicting changes in the relationship between supervisors and workers. It may increase cooperation and helping effort. At the same time it can increase direct monitoring and pressure by the supervisor, and mutual monitoring and peer pressure from other workers that is transmitted through the supervisor. Using data on satisfaction with the boss, we initially show that workers under profit sharing tend to have lower satisfaction with their supervisor. Additional estimates show this is largely generated by groups of workers who would be least likely to respond to increased supervisory pressure with increase effort: women, those with dependents and those with health limitations. Despite this finding, profit sharing seems to have little or no influence on overall job satisfaction as the reduction in satisfaction with the boss is offset with increased satisfaction with earnings, a finding consistent with profit sharing enhancing productivity and earnings.

Unions, Dissatisfied Workers and Sorting

A persistent and sizeable literature argues that the reported job dissatisfaction of union members is spurious. It reflects either the sorting of workers across union status or the sorting of union recognition across jobs. We cast doubt on this argument presenting the first estimates that use panel data to hold constant both worker and job match fixed effects. The estimates demonstrate that covered union members report greater dissatisfaction even when accounting for sorting in both dimensions. Moreover, covered union members are less likely to quit holding job satisfaction constant and their quit behaviour is far less responsive to job satisfaction. The paradox of the discontented union member remains intact.

Does profit sharing increase training by reducing turnover?

We test the theoretical prediction that profit sharing reduces worker separations and by doing so increases the incidence of training. Using individual level UK data, we confirm that profit sharing is a robust determinant of lower separation rates and of greater training incidence. Critically, we cannot confirm the predicted link between separations and training. Instead, the evidence supports alternative theories suggesting a direct link between profit sharing and training. Our results suggest that profit sharing changes employer-worker relations in a way that leads to greater formal and informal investment in worker skills but that this is independent of its influence on reducing separations.

Are flexible contracts bad for workers? Evidence from job satisfaction data

If workers can choose between permanent and flexible contracts, compensating wage differentials should arise to equalize on-the-job utility in the two types of contracts. Estimating job satisfaction using the British Household Panel Survey shows that agency and casual contracts are associated with routinely lower satisfaction. This results because the low job satisfaction associated with less job security is not offset by higher compensation or other job characteristics. Job security is sufficiently important that holding constant this one facet of satisfaction eliminates the overall gap in job satisfaction between flexible and permanent contracts.

Performance pay, sorting and the dimensions of job satisfaction

This paper investigates the influence of performance related pay on several dimensions of job satisfaction. In cross-sectional estimates, performance related pay is associated with increased overall satisfaction, satisfaction with pay, satisfaction with job security and satisfaction with hours. It appears to be negatively associated with satisfaction with the work itself. Yet, after accounting for worker fixed-effects, the positive associations remain and the negative association vanishes. These results appear robust to a variety of alternative specifications and support the notion that performance pay allows increased opportunities for worker optimization and do not generally demotivate workers or crowd out intrinsic motivation.

Underwater optical wireless communications : depth dependent variations in attenuation

Depth variations in the attenuation coefficient for light in the ocean were calculated using a one-parameter model based on the chlorophyll-a concentration Cc and experimentally-determined Gaussian chlorophyll-depth profiles. The depth profiles were related to surface chlorophyll levels for the range 0–4  mg/m2, representing clear, open ocean. The depth where Cc became negligible was calculated to be shallower for places of high surface chlorophyll; 111.5 m for surface chlorophyll 0.8<Cc<2.2  mg/m3 compared with 415.5 m for surface Cc<0.04  mg/m3. Below this depth is the absolute minimum attenuation for underwater ocean communication links, calculated to be 0.0092  m−1 at a wavelength of 430 nm. By combining this with satellite surface-chlorophyll data, it is possible to quantify the attenuation between any two locations in the ocean, with applications for low-noise or secure underwater communications and vertical links from the ocean surface

Millimeter wave experiment for ATS-F

A detailed description of spaceborne equipment is provided. The equipment consists of two transmitters radiating signals at 20 and 30 GHz from either U.S. coverage horn antennas or a narrow beam parabolic antenna. Three modes of operation are provided: a continuous wave mode, a multitone mode in which nine spectral lines having 180 MHz separation and spaced symmetrically about each carrier, and a communications mode in which communications signals from the main spacecraft transponder are modulated on the two carriers. Detailed performance attained in the flight/prototype model of the equipment is presented both under laboratory conditions and under environmental extremes. Provisions made for ensuring reliability in space operation are described. Also described the bench test equipment developed for use with the experiment, and a summary of the new technology is included