72,704 research outputs found
Evaluating Judges and Judicial Institutions: Reorienting the Perspective
Empirical scholarship on judges, judging, and judicial institutions, a staple in political science, is becoming increasingly popular in law schools. We propose that this scholarship can be improved and enhanced by greater collaboration between empirical scholars, legal theorists, and the primary subjects of the research, the judges. We recently hosted a workshop that attempted to move away from the conventional mode of involving judges and theorists in empirical research, where they serve as commentators on empirical studies that they often see as reductionist and mis-focused. Instead, we had the judges and theorists set the discussion agenda for the empiricists by describing topics that they thought were worthy of inquiry. In this essay, we explain why we think collaboration of this sort should be encouraged and draw on the workshop experience to offer suggestions for improving the quality and utility of empirical research in this area
Sampling and reconstruction of operators
We study the recovery of operators with bandlimited Kohn-Nirenberg symbol
from the action of such operators on a weighted impulse train, a procedure we
refer to as operator sampling. Kailath, and later Kozek and the authors have
shown that operator sampling is possible if the symbol of the operator is
bandlimited to a set with area less than one. In this paper we develop explicit
reconstruction formulas for operator sampling that generalize reconstruction
formulas for bandlimited functions. We give necessary and sufficient conditions
on the sampling rate that depend on size and geometry of the bandlimiting set.
Moreover, we show that under mild geometric conditions, classes of operators
bandlimited to an unknown set of area less than one-half permit sampling and
reconstruction. A similar result considering unknown sets of area less than one
was independently achieved by Heckel and Boelcskei.
Operators with bandlimited symbols have been used to model doubly dispersive
communication channels with slowly-time-varying impulse response. The results
in this paper are rooted in work by Bello and Kailath in the 1960s.Comment: Submitted to IEEE Transactions on Information Theor
Quantum diffusion in liquid water from ring polymer molecular dynamics
We have used the ring polymer molecular-dynamics method to study the translational and orientational motions in an extended simple point charge model of liquid water under ambient conditions. We find, in agreement with previous studies, that quantum-mechanical effects increase the self-diffusion coefficient D and decrease the relaxation times around the principal axes of the water molecule by a factor of around 1.5. These results are consistent with a simple Stokes-Einstein picture of the molecular motion and suggest that the main effect of the quantum fluctuations is to decrease the viscosity of the liquid by about a third. We then go on to consider the system-size scaling of the calculated self-diffusion coefficient and show that an appropriate extrapolation to the limit of infinite system size increases D by a further factor of around 1.3 over the value obtained from a simulation of a system containing 216 water molecules. These findings are discussed in light of the widespread use of classical molecular-dynamics simulations of this sort of size to model the dynamics of aqueous systems
Dollarization and monetary sovereignty: the case of Argentina
In January, President Menim of Argentina proposed strengthening his country's commitment to monetary stability by replacing the peso with the U.S. dollar. Dollarization leaves Argentina without a lender of last resort, but the Federal Reserve's current operating procedure combines with existing Argentine arrangements to mitigate this drawback.Argentina ; Monetary policy - Argentina ; Currency boards
Reformulating empirical macro-econometric modelling
The policy implications of estimated macro-econometric systems depend on the formulations of their equations, the methodology of empirical model selection and evaluation, the techniques of policy analysis, and their forecast performance. Drawing on recent results in the theory of forecasting, we question the role of `rational expectations'; criticize a common approach to testing economic theories; show that impulse-response methods of evaluating policy are seriously flawed; and question the mechanistic derivation of forecasts from econometric systems. In their place, we propose that expectations should be treated as instrumental to agents' decisions; discuss a powerful new approach to the empirical modelling of econometric relationships; offer viable alternatives to studying policy implications; and note modifications to forecasting devices that can enhance their robustness to unanticipated structural breaks. Keywords; economic policy analysis, macro-econometric systems, empirical model selection and evaluation, forecasting, rational expectations, impulse-response analysis, structural breaks
MARKET STRUCTURE AND INNOVATION INTENSITY IN AGRICULTURAL BIOTECH
Consolidations and spin-offs in the agricultural biotechnology industry and the growing links of multinational corporations with the food and feed industry have been the subject of considerable discussion among academics, policy makers, consumers, and farmers. Most of the research by academic and overnment institutions has focused on the reasons for consolidation. Little theoretical or empirical research has examined the impact of this consolidation. We adapt an endogenous growth model of industry structure and R&D to agricultural biotechnology and empirically estimate the model. These empirical estimates, the main focus of the paper, indicate that industry consolidation influences the amount and direction of research, which then feeds back to influence industry structure.Agribusiness, Marketing, Research and Development/Tech Change/Emerging Technologies,
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