Why do states commit to international human rights treaties that may limit state sovereignty? Existing arguments focus on either the fear of domestic democratic instability or on international norms. We focus instead on the variation in three kinds of costs that states must pay to commit: policy change, unintended consequences, and limited flexibility. We use a discrete time-duration model to t...

To control the deer population, state game commissions regulate the types of deer that can be legally harvested. These regulations, however, might have an unintended effect on hunting-related accidents by changing the care hunters take when firing their rifles—a moral hazard effect—or changing the composition of hunters. Using detailed data on hunting accidents and regulations in Pennsylvania c...

In this research work, we have a didactical look on the integration of a computer tool into mathematics teaching: the spreadsheet. We have related research about spreadsheet to an instrumental approach perceived as essential to analyze the questions of technological integration. This approach allowed us to extend to this technology the theoretical framework of instrumentation. These theoretical...

This paper examines how Congress’s 2008 expansion of who is disabled under the Americans with Disabilities Act (ADA) impacts the labor market outcomes of newly covered individuals. Focusing on obese individuals, I exploit variation in coverage of obesity before and after the 2008 expansion to identify effects of the legal change, but I find no improvement in the labor market outcomes of the obe...

Let G be a reductive, connected algebraic group over an algebraic closure of a finite field. We define a tensor structure on the category of perverse sheaves on G which are direct sums of unipotent character sheaves in a fixed two-sided cell; we show that this is equivalent to the centre with a known monoidal abelian category (a categorification of the J-ring associated to the same two-sided ce...

During the FOS-DECAFE experiment at Lamto, Ivory Coast, in January 1991, various ground studies were undertaken simultaneously in order to investigate the physical and chemical characteristics of smoke emitted by savanna biomass burning. Here we present sunphotometer groundbased results which allow the measurements of the spectral optical depth between 450 and 850 nm, the atmospheric water vapo...

The dependence atom =(x, y) was introduced in [11]. Here x and y are finite sets of attributes (or variables) and the intuitive meaning of =(x, y) is that the attributes x completely (functionally) determine the attributes y. One may wonder, whether the dependence atom is truly an atom or whether it has further constituents. My very pleasant co-operation with Samson Abramsky led to the breaking...

Using multiple point spaces some new examples of perverse sheaves on images of maps are described. Furthermore, suppose f : X ! Y is a nite and proper map of complex analytic manifolds of dimension n and n + 1 such that every multiple point space is non-singular and has the dimension expected of a generic map. Then we can describe the composition series for the constant sheaf on the image in th...

Measuring and comparing performance in local government is controversial for good reasons. When these initiatives expand beyond purely academic considerations and are implemented in practice, several unintended consequences are likely to arise. These include an excessive focus on particular aspects of governance, strategic responses to maximise scores, unaccounted effects of exogenous variables...

We review recent work in which compactifications of string and M theory are constructed in which all scalar fields (moduli) are massive, and supersymmetry is broken with a small positive cosmological constant, features needed to reproduce real world physics. We explain how this work implies that there is a “landscape” of string/M theory vacua, perhaps containing many candidates for describing r...