5,268 research outputs found
Advancing the Empirical Research on Lobbying
This essay identifies the empirical facts about lobbying which are generally agreed upon in the literature. It then discusses challenges to empirical research in lobbying and provides examples of empirical methods that can be employed to overcome these challenges—with an emphasis on statistical measurement, identification, and casual inference. The essay then discusses the advantages, disadvantages, and effective use of the main types of data available for research in lobbying. It closes by discussing a number of open questions for researchers in the field and avenues for future work to advance the empirical research in lobbying
Coalescent simulation in continuous space:Algorithms for large neighbourhood size
Many species have an essentially continuous distribution in space, in which there are no natural divisions between randomly mating subpopulations. Yet, the standard approach to modelling these populations is to impose an arbitrary grid of demes, adjusting deme sizes and migration rates in an attempt to capture the important features of the population. Such indirect methods are required because of the failure of the classical models of isolation by distance, which have been shown to have major technical flaws. A recently introduced model of extinction and recolonisation in two dimensions solves these technical problems, and provides a rigorous technical foundation for the study of populations evolving in a spatial continuum. The coalescent process for this model is simply stated, but direct simulation is very inefficient for large neighbourhood sizes. We present efficient and exact algorithms to simulate this coalescent process for arbitrary sample sizes and numbers of loci, and analyse these algorithms in detail
Scale-invariance in gravity and implications for the cosmological constant
Recently a scale invariant theory of gravity was constructed by imposing a
conformal symmetry on general relativity. The imposition of this symmetry
changed the configuration space from superspace - the space of all Riemannian
3-metrics modulo diffeomorphisms - to conformal superspace - the space of all
Riemannian 3-metrics modulo diffeomorphisms and conformal transformations.
However, despite numerous attractive features, the theory suffers from at least
one major problem: the volume of the universe is no longer a dynamical
variable. In attempting to resolve this problem a new theory is found which has
several surprising and atractive features from both quantisation and
cosmological perspectives. Furthermore, it is an extremely restrictive theory
and thus may provide testable predictions quickly and easily. One particularly
interesting feature of the theory is the resolution of the cosmological
constant problem.Comment: Replaced with final version: minor changes to text; references adde
Subcontracts—Part Performance—Damages.—Albre Marble and Tile Co., Inc. v. John Bowen Co., Inc.
- …