Local asymptotic minimax risk bounds in a locally asymptotically mixture of normal experiments under asymmetric loss

Local asymptotic minimax risk bounds in a locally asymptotically mixture of normal family of distributions have been investigated under asymmetric loss functions and the asymptotic distribution of the optimal estimator that attains the bound has been obtained.Comment: Published at http://dx.doi.org/10.1214/074921706000000527 in the IMS Lecture Notes--Monograph Series (http://www.imstat.org/publications/lecnotes.htm) by the Institute of Mathematical Statistics (http://www.imstat.org

Scaling and universality in coupled driven diffusive models

Inspired by the physics of magnetohydrodynamics (MHD) a simplified coupled Burgers-like model in one dimension (1d), a generalization of the Burgers model to coupled degrees of freedom, is proposed to describe 1dMHD. In addition to MHD, this model serves as a 1d reduced model for driven binary fluid mixtures. Here we have performed a comprehensive study of the universal properties of the generalized d-dimensional version of the reduced model. We employ both analytical and numerical approaches. In particular, we determine the scaling exponents and the amplitude-ratios of the relevant two-point time-dependent correlation functions in the model. We demonstrate that these quantities vary continuously with the amplitude of the noise cross-correlation. Further our numerical studies corroborate the continuous dependence of long wavelength and long time-scale physics of the model on the amplitude of the noise cross-correlations, as found in our analytical studies. We construct and simulate lattice-gas models of coupled degrees of freedom in 1d, belonging to the universality class of our coupled Burgers-like model, which display similar behavior. We use a variety of numerical (Monte-Carlo and Pseudospectral methods) and analytical (Dynamic Renormalization Group, Self-Consistent Mode-Coupling Theory and Functional Renormalization Group) approaches for our work. The results from our different approaches complement one another. Possible realizations of our results in various nonequilibrium models are discussed.Comment: To appear in JSTAT (2009); 52 pages in JSTAT format. Some figure files have been replace

A Theory of Decision-Making

In a separate article, it has been stated: The kinds of theories which social scientists have been able to construct have largely been dependent on the level or the degree of inference which the researchers have been able to draw from observations or experimental designs (which may or may not reflect the empirical world), and the assumptions upon which these inferences rest (Basu and Kenyon, 1972.425). Notably, in the past three decades the eventual success of a theory has been tested on this basis. A major underlying premise in the ideographic science has been that cause and effect represent the methodological level of inquiry, however singularizing (as opposed to nomothetic generalizing science) the social experience may be. These relationships are either asymetric, assming an independent-dependent variable dichotomy, or symmetric, i.e. constructing theory on the basis of an interdependent, reciprocal causation Inference. These analytic frames have attempted to explain what Darkheim has called soclal facts. However, the problems of limitation of such a search In the development and finally application of a social theory using causal inferences as methodological guidelines have cam to light, specifically In the area of policy-planning and decision making. It is the purpose of this paper to attempt to extend theory (specifically that applying to policy-planning and decision-making) from these limitations. The author win propose a theory of decision-making and will suggest its applications

State-Level and County-Level Estimates of Health Care Costs Associated with Food Insecurity.

IntroductionFood insecurity, or uncertain access to food because of limited financial resources, is associated with higher health care expenditures. However, both food insecurity prevalence and health care spending vary widely in the United States. To inform public policy, we estimated state-level and county-level health care expenditures associated with food insecurity.MethodsWe used linked 2011-2013 National Health Interview Survey/Medical Expenditure Panel Survey data (NHIS/MEPS) data to estimate average health care costs associated with food insecurity, Map the Meal Gap data to estimate state-level and county-level food insecurity prevalence (current though 2016), and Dartmouth Atlas of Health Care data to account for local variation in health care prices and intensity of use. We used targeted maximum likelihood estimation to estimate health care costs associated with food insecurity, separately for adults and children, adjusting for sociodemographic characteristics.ResultsAmong NHIS/MEPS participants, 10,054 adults and 3,871 children met inclusion criteria. Model estimates indicated that food insecure adults had annual health care expenditures that were $1,834 (95$1,073-2,595, P < .001) higher than food secure adults. For children, estimates were 80 higher, but this finding was not significant (95% CI, -$171 to$329, P = .53). The median annual health care cost associated with food insecurity was $687,041,000 (25th percentile,$239,675,000; 75th percentile, $1,140,291,000). The median annual county-level health care cost associated with food insecurity was$4,433,000 (25th percentile, $1,774,000; 75th percentile,$11,267,000). Cost variability was related primarily to food insecurity prevalence.ConclusionsHealth care expenditures associated with food insecurity vary substantially across states and counties. Food insecurity policies may be important mechanisms to contain health care expenditures

Fixed-Energy Sandpiles Belong Generically to Directed Percolation

Fixed-energy sandpiles with stochastic update rules are known to exhibit a nonequilibrium phase transition from an active phase into infinitely many absorbing states. Examples include the conserved Manna model, the conserved lattice gas, and the conserved threshold transfer process. It is believed that the transitions in these models belong to an autonomous universality class of nonequilibrium phase transitions, the so-called Manna class. Contrarily, the present numerical study of selected (1+1)-dimensional models in this class suggests that their critical behavior converges to directed percolation after very long time, questioning the existence of an independent Manna class.Comment: article (4 pages, 9 eps figures) + Supplement (8 pages, 9 eps figures); Phys. Rev. Lett. 201