Management, Control, and the Dilemmas of Presidential Leadership in the Modern Administrative State

To assess the virtues of strong presidential leadership in the regulatory process, we need to have a richer sense of the dimensions of presidential leadership in regulatory decisionmaking. The set of proposals put forward by the National Performance Review (NPR), a task force established by the Clinton administration last year, provides a useful focal point for the examination of this issue. In Part I, the author considers how the trend toward President-led initiatives fits with our growing skepticism about the capacities of legislators and bureaucrats to improve regulation and administration. In Part II, the author traces some of the conceptual underpinnings of the President\u27s expanding regulatory role. The author adds to this mostly theoretical discussion the particulars of the NPR Report in Part III. Ultimately, the Clinton administration\u27s opening salvo into the thicket of regulatory reform is of a piece with contemporary trends in presidential politics and regulatory administration

Physics of beer tapping

The popular bar prank known in colloquial English as beer tapping consists in hitting the top of a beer bottle with a solid object, usually another bottle, to trigger the foaming over of the former within a few seconds. Despite the trick being known for long time, to the best of our knowledge, the phenomenon still lacks scientific explanation. Although it seems natural to think that shock-induced cavitation enhances the diffusion of CO$_2$ from the supersaturated bulk liquid into the bubbles by breaking them up, the subtle mechanism by which this happens remains unknown. Here we show that the overall foaming-over process can be divided into three stages where different physical phenomena take place in different time-scales, namely: bubble-collapse (or cavitation) stage, diffusion-driven stage and buoyancy-driven stage. In the bubble-collapse stage, the impact generates a train of expansion-compression waves in the liquid that leads to the fragmentation of pre-existing gas cavities. Upon bubble fragmentation, the sudden increase of the interface-area-to-volume ratio enhances mass transfer significantly, which makes the bubble volume grow by a large factor until CO$_2$ is locally depleted. At that point buoyancy takes over, making the bubble clouds rise and eventually form buoyant vortex rings whose volume grows fast due to the feedback between the buoyancy-induced rising speed and the advection-enhanced CO$_2$ transport from the bulk liquid to the bubble. The physics behind this explosive process might also be connected to some geological phenomena.Comment: 7 pages, 4 figures, 4 movies Accepted in Physical Review Letter

Explaining changes in the age distribution of displaced workers

Using Displaced Worker Survey data, this paper examines changes in the age distribution of displaced workers during the 1983–87 and 1993–97 periods. Older workers comprised a significantly larger fraction of displaced workers during the later period. Potential explanations for this phenomenon include demographic shifts in the labor force, changes in technology, and industry and occupational shifts. Kernel density estimates indicate that the aging of the labor force accounts for the majority of the shift in the age distribution of displaced workers. Changes in technology also appear to have contributed to the shift in the age distribution of displaced workers by increasing the likelihood of displacement among older workers relative to younger workers. Differential changes across age groups between goods-producing and service-producing jobs and between blue-collar and white-collar jobs appear to have had little effect on the change in the age distribution of displaced workers.Labor turnover ; Demography ; Labor supply