8,598 research outputs found
The 2-adic Eigencurve is Proper
For p=2 and tame level N=1 we prove that the map from the (Coleman-Mazur)
Eigencurve to weight space satisfies the valuative criterion of properness.
More informally, we show that the Eigencurve has no "holes"; given a punctured
disc of finite slope overconvergent eigenforms over weight space, the center
can be "filled in" with a finite slope overconvergent eigenform
The recursive nature of cominuscule Schubert calculus
The necessary and sufficient Horn inequalities which determine the
non-vanishing Littlewood-Richardson coefficients in the cohomology of a
Grassmannian are recursive in that they are naturally indexed by non-vanishing
Littlewood-Richardson coefficients on smaller Grassmannians. We show how
non-vanishing in the Schubert calculus for cominuscule flag varieties is
similarly recursive. For these varieties, the non-vanishing of products of
Schubert classes is controlled by the non-vanishing products on smaller
cominuscule flag varieties. In particular, we show that the lists of Schubert
classes whose product is non-zero naturally correspond to the integer points in
the feasibility polytope, which is defined by inequalities coming from
non-vanishing products of Schubert classes on smaller cominuscule flag
varieties. While the Grassmannian is cominuscule, our necessary and sufficient
inequalities are different than the classical Horn inequalities.Comment: 41 pages, revisions to improve clarity of expositio
00-03 "Trade Liberalization and Pollution Intensive Industries in Developing Countries: A Partial Equilibrium Approach."
Economic theory suggests that liberalization of trade between countries with differing levels of environmental protection could lead pollution-intensive industry to concentrate in the nations where regulations are lax. This effect, often referred to as the "pollution haven" hypothesis, is much discussed in theory, but finds only ambiguous support in empirical research to date. Methodologies used for research on trade and environment differ widely; many are difficult to apply to practical policy questions. We develop a simple, partial equilibrium model explicitly designed to analyze the effects of a change in trade policy. Our model analyzes the relative concentrations of "clean" and "dirty" industries in two nations or regions, before and after the policy change. While lacking the theoretical rigor and mathematical intricacy of other modeling methods, our approach has the advantages of transparency and accessibility to a broad range of analysts and policy makers.
"Mixed Signals: Market Incentives, Recycling, and the Price Spike of 1995"
Environmental economics assumes that reliance on price signals, adjusted for externalities, normally leads to efficient solutions to environmental problems. We explore a limiting case, when market volatility created âmixed signalsâ: waste paper and other recycled materials were briefly worth an immense amount in 1994-95, then plummeted back to traditional low levels in 1996. These rapid reversals resulted in substantial economic and political costs. A review of academic and business literature suggests six possible explanations for abrupt price spikes. An econometric analysis of the prices of wood pulp and waste paper shows that factors that explained price changes in 1983- 93 contribute very little to understanding the subsequent price spike. From the econometric analysis and from other sources, we conclude that speculation, rather than ârationalâ economic factors, must have played a major role in the price spike. If speculatively driven price spikes can disrupt an environmentally important industry such as recycling, then the surprising implication for public policy is that measures to control or stabilize prices, far from interfering with the market, may actually help to make it more efficient.price spike, recycling, economic policy, market volatility
01-02 "Mixed Signals: Market Incentives, Recycling, and the Price Spike of 1995"
Environmental economics assumes that reliance on price signals, adjusted for externalities, normally leads to efficient solutions to environmental problems. We explore a limiting case, when market volatility created "mixed signals": waste paper and other recycled materials were briefly worth an immense amount in 1994-95, then plummeted back to traditional low levels in 1996. These rapid reversals resulted in substantial economic and political costs. A review of academic and business literature suggests six possible explanations for abrupt price spikes. An econometric analysis of the prices of wood pulp and waste paper shows that factors that explained price changes in 1983-93 contribute very little to understanding the subsequent price spike. From the econometric analysis and from other sources, we conclude that speculation, rather than "rational" economic factors, must have played a major role in the price spike. If speculatively driven price spikes can disrupt an environmentally important industry such as recycling, then the surprising implication for public policy is that measures to control or stabilize prices, far from interfering with the market, may actually help to make it more efficient.
00-05 "Getting the Prices Wrong: The Limits of Market-Based Environmental Policy."
Market based policies are fast becoming the recommended policy panacea for all the world's environmental problems. Implicit in such recommendations is the theory that free markets, adjusted for externalities, can always create an "efficient" allocation of society's resources. As a result, many contemporary policymakers advocate rolling back regulations in order to let the market protect the environment. There is a fundamental distinction between the use of the market as a tool to help achieve society's goals, and as a blueprint for society's goals; the market is a reasonable policy tool but not a reasonable blueprint. The market as blueprint fails because there are significant public purposes that cannot be achieved by prices and markets alone. Five major arguments show that getting the prices right is often a narrow or meaningless objective; society may intentionally and appropriately choose to "get the prices wrong" in order to pursue more important goals.
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