A calibrated radiocarbon database of late Quaternary volcanic eruptions

International audienceResearchers at the Center for Climatic Research (CCR) at the University of Wisconsin-Madison have revised and calibrated a global volcanic database compiled from more than 2000 radiocarbon-dated eruptions from the late Pleistocene and Holocene. The updated database is available online as an appendix to this correspondence (http://www.electronic-earth-discuss.net/1/123/2006/eed-1-123-2006-supplement.zip). We briefly describe the database, suggest some potential applications, and invite other researchers in the geologic and atmospheric sciences to both use and help refine the archive by incorporating additional data as it becomes available

Do Salaries Improve Worker Performance?

We establish the effects of salaries on worker performance by exploiting a natural experiment in which some workers in a particular occupation (football referees) switch from short-term contracts to salaried contracts. Worker performance improves among those who move onto salaried contracts relative to those who do not. The finding is robust to the introduction of worker fixed effects indicating that it is not driven by better workers being awarded salary contracts. Nor is it sensitive to workers sorting into or out of the profession. Improved performance could arise from the additional effort workers exert due to career concerns, the higher income associated with career contracts (an efficiency wage effect) or improvements in worker quality arising from off-the-job training which accompanies the salaried contracts.

Smoothing for time-varying systems using measurements containing colored noise

Optimal smoother derived for linear time-varying systems using measurements containing colored noise by means of calculus of variation

Soil penetrometer

An auger-type soil penetrometer for burrowing into soil formations is described. The auger, while initially moving along a predetermined path, may deviate from the path when encountering an obstruction in the soil. Alterations and modifications may be made in the structure so that it may be used for other purposes

From the Two Faces of Unionism to the Facebook Society: Union Voice in a 21st Century Context, Manpower Human Resources Lab Discussion Paper No. 6

Union membership has declined precipitously in the US over the past 40 years. Can anything be done to stem this decline? This paper argues that union voice is an attribute (among others) of union membership that is experiential in nature and that unlike the costs of unionisation, can be discerned only after joining a union. This makes the act of ‘selling’ unionism to workers (and to some extent firms as well) rather difficult. Supportive social trends and social customs are required in order to make union membership’s many hard-to-observe benefits easier to discern. Most membership based institutions face the same dilemma. However, recent social networking organizations such as Facebook and other on-line communities have been rather successful in attracting millions of members in a relatively short period of time. The question of whether the union movement can appropriate some of these lessons is discussed with reference to historical and contemporary examples

The separate computation of arcs for optimal flight paths with state variable inequality constraints

Computation of arcs for optimal flight paths with state variable inequality constraint

Correlation of currents with the distribution of adult daphnia in Lake Mendota

Simultaneous observations of current pattern and distribution of Daphnia pulex indicate that in Lake Mendota this zooplankter is concentrated by wind-induced convergence. Theoretical examination of this hypothesis yields results which compare favorably with observations

Youth-Adult Differences in the Demand for Unionization: Are American, British and Canadian Workers All That Different?

This paper examines demand for union membership amongst young workers in Britain, Canada and the United States. The paper benchmarks youth demands for collective representation against those of adult workers and finds that a large and significant representation gap exists in all three countries. Using a model of representation advanced by Farber (1982) and Riddell (1993) we find that a majority of the union density differential between young and adult workers is due to supply-side constraints rather than a lower desire for unionisation on the part of the young. This finding lends credence to two conjectures made in the paper; the first is that tastes for collective representation do not differ among workers (either by nationality or by age) and second that union representation can be fruitfully modelled as an experience good. The experience good properties of union membership explain the persistence of union density differentials amongst youth and adults both over time and across countries