Dynamic Reserves in Matching Markets

We study a school choice problem under affirmative action policies where authorities reserve a certain fraction of the slots at each school for specific student groups, and where students have preferences not only over the schools they are matched to but also the type of slots they receive. Such reservation policies might cause waste in instances of low demand from some student groups. To propose a solution to this issue, we construct a family of choice functions, dynamic reserves choice functions, for schools that respect within-group fairness and allow the transfer of otherwise vacant slots from low-demand groups to high-demand groups. We propose the cumulative offer mechanism (COM) as an allocation rule where each school uses a dynamic reserves choice function and show that it is stable with respect to schools' choice functions, is strategy-proof, and respects improvements. Furthermore, we show that transferring more of the otherwise vacant slots leads to strategy-proof Pareto improvement under the COM

Linear/Quadratic Programming-Based Optimal Power Flow using Linear Power Flow and Absolute Loss Approximations

This paper presents novel methods to approximate the nonlinear AC optimal power flow (OPF) into tractable linear/quadratic programming (LP/QP) based OPF problems that can be used for power system planning and operation. We derive a linear power flow approximation and consider a convex reformulation of the power losses in the form of absolute value functions. We show four ways how to incorporate this approximation into LP/QP based OPF problems. In a comprehensive case study the usefulness of our OPF methods is analyzed and compared with an existing OPF relaxation and approximation method. As a result, the errors on voltage magnitudes and angles are reasonable, while obtaining near-optimal results for typical scenarios. We find that our methods reduce significantly the computational complexity compared to the nonlinear AC-OPF making them a good choice for planning purposes

On a Recently Introduced Fifth-Order Bi-Hamiltonian Equation and Trivially Related Hamiltonian Operators

We show that a recently introduced fifth-order bi-Hamiltonian equation with a differentially constrained arbitrary function by A. de Sole, V.G. Kac and M. Wakimoto is not a new one but a higher symmetry of a third-order equation. We give an exhaustive list of cases of the arbitrary function in this equation, in each of which the associated equation is inequivalent to the equations in the remaining cases. The equations in each of the cases are linked to equations known in the literature by invertible transformations. It is shown that the new Hamiltonian operator of order seven, using which the introduced equation is obtained, is trivially related to a known pair of fifth-order and third-order compatible Hamiltonian operators. Using the so-called trivial compositions of lower-order Hamiltonian operators, we give nonlocal generalizations of some higher-order Hamiltonian operators

Why did it work this time: a comparative analysis of transformation of Turkish economy after 2002

Turkey had several unsuccessful stabilization efforts during 1980s and 1990s. Thanks to policies that were put into practice after the 2001 crisis, which constitutes a turning point for Turkish economy, fiscal discipline was restored, single digit inflation was reached, and yet growth rate was doubled compared to the previous decade average. As a result investment climate improved and the economy benefited from substantial amount of foreign direct investment and other long-term capital inflows. However these developments had some adverse side effects as well. Real appreciation of domestic currency, deterioration of trade balance, and increasing private indebtedness generated vulnerability for sudden stops. Beside, increasing global integration and very rapid shift in the economic circumstances caused difficulties for traditional sectors. This paper analyzes the Turkish experience after 2001 and identifies underlying dynamics of the restructuring program, while denoting the costs of this transition. Turkish case provides evidence in favor of disinflation programs combined with sound fiscal policies in spite of some adverse effects in the short run.Turkish Economy, Crisis, Stabilization Policy, Macroeconomic Performance

Beyond the global financial crisis: central banking in a new global financial system

Since the outbreak of the global crisis in mid 2007, there has been an extensive discussion on root causes. Some blame the greed and corruption of financial actors. Others put the blame on central bankers for easy money or regulators who remained idle as too much risks accumulated in financial markets. According to advanced economies, global imbalances have been caused by emerging surplus countries that keep their currency undervalued and their domestic consumption restricted. It is unfortunate that all these arguments and counter arguments, which may be valid in their own way, prevents a more general discussion on the deep-seated conflicts and contradictions in the global economic, social and political paradigm upon which the world order is built. To put it another way, the problems we face today do not arise from some operational failures, but from the system itself and the underlying philosophical framework. In fact this is a crisis of three main pillars of our existing system: the crisis of the economic theory, the crisis of the globalization, and the crisis of market based financial system.global financial crisis, economic theory, financial system

Non-autonomous Svinolupov Jordan KdV Systems

Non-autonomous Svinolupov-Jordan systems are considered. The integrability criteria of such systems are associated with the existence of recursion operators. A new non-autonomous KdV system is obtained and its recursion operator is given for all $N$. The examples for N=2 and N=3 are studied in detail. Some possible transformations are also discussed which map some systems to autonomous cases.Comment: Latex file (amssymb), 10 page