19,236 research outputs found
Political Settlements: Issues paper
Why do similar sets of formal institutions often have such divergent outcomes? An analysis of political settlements goes some way to answering this question by bringing into focus the contending interests that exist within any state, which constrain and facilitate institutional and developmental change. It provides a framework to analyse how the state is linked to society and what lies behind the formal representation of politics in a state.
The political settlement and the elite bargains from which it emerges are central to patterns of state fragility and resilience. The role of political organisation within the political settlement is crucial to both the stability of the settlement and the direction in which it evolves over time. The elite bargains that may lead to the establishment of what might be considered a resilient political settlement may also act as a barrier to progressive developmental change.
Analysis of political settlements suggests that state-building is far from a set of technical formulas, but is a highly political process. Creating capacity within a state to consolidate and expand taxation is fundamentally determined by the shape of the political settlement underlying the state. This is true as well for the development of service delivery or any other function of the state. This analytical framework provides a window for donors to grasp the politics of a place in order to design more effective interventions
The Political Economy of Taxation and Tax Reform in Developing Countries
taxation, tax reform, political economy, state capacity, developing countries
A note on Stokes' problem in dense granular media using the --rheology
The classical Stokes' problem describing the fluid motion due to a steadily
moving infinite wall is revisited in the context of dense granular flows of
mono-dispersed beads using the recently proposed --rheology. In
Newtonian fluids, molecular diffusion brings about a self-similar velocity
profile and the boundary layer in which the fluid motion takes place increases
indefinitely with time as , where is the kinematic
viscosity. For a dense granular visco-plastic liquid, it is shown that the
local shear stress, when properly rescaled, exhibits self-similar behaviour at
short-time scales and it then rapidly evolves towards a steady-state solution.
The resulting shear layer increases in thickness as analogous
to a Newtonian fluid where is an equivalent granular kinematic
viscosity depending not only on the intrinsic properties of the granular media
such as grain diameter , density and friction coefficients but also
on the applied pressure at the moving wall and the solid fraction
(constant). In addition, the --rheology indicates that this growth
continues until reaching the steady-state boundary layer thickness , independent of the grain size, at about a finite
time proportional to , where is
the acceleration due to gravity and is the
relative surplus of the steady-state wall shear-stress over the
critical wall shear stress (yield stress) that is needed to bring the
granular media into motion... (see article for a complete abstract).Comment: in press (Journal of Fluid Mechanics
Electron turbulence at nanoscale junctions
Electron transport through a nanostructure can be characterized in part using
concepts from classical fluid dynamics. It is thus natural to ask how far the
analogy can be taken, and whether the electron liquid can exhibit nonlinear
dynamical effects such as turbulence. Here we present an ab-initio study of the
electron dynamics in nanojunctions which reveals that the latter indeed
exhibits behavior quite similar to that of a classical fluid. In particular, we
find that a transition from laminar to turbulent flow occurs with increasing
current, corresponding to increasing Reynolds numbers. These results reveal
unexpected features of electron dynamics and shed new light on our
understanding of transport properties of nanoscale systems.Comment: 5 pages, 3 figure
Contraction analysis of switched Filippov systems via regularization
We study incremental stability and convergence of switched (bimodal) Filippov
systems via contraction analysis. In particular, by using results on
regularization of switched dynamical systems, we derive sufficient conditions
for convergence of any two trajectories of the Filippov system between each
other within some region of interest. We then apply these conditions to the
study of different classes of Filippov systems including piecewise smooth (PWS)
systems, piecewise affine (PWA) systems and relay feedback systems. We show
that contrary to previous approaches, our conditions allow the system to be
studied in metrics other than the Euclidean norm. The theoretical results are
illustrated by numerical simulations on a set of representative examples that
confirm their effectiveness and ease of application.Comment: Preprint submitted to Automatic
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