Exchange Rate Models Are Not as Bad as You Think

Standard models of exchange rates, based on macroeconomic variables such as prices, interest rates, output, etc., are thought by many researchers to have failed empirically. We present evidence to the contrary. First, we emphasize the point that "beating a random walk" in forecasting is too strong a criterion for accepting an exchange rate model. Typically models should have low forecasting power of this type. We then propose a number of alternative ways to evaluate models. We examine in-sample fit, but emphasize the importance of the monetary policy rule, and its effects on expectations, in determining exchange rates. Next we present evidence that exchange rates incorporate news about future macroeconomic fundamentals, as the models imply. We demonstrate that the models might well be able to account for observed exchange-rate volatility. We discuss studies that examine the response of exchange rates to announcements of economic data. Then we present estimates of exchange-rate models in which expected present values of fundamentals are calculated from survey forecasts. Finally, we show that out-of-sample forecasting power of models can be increased by focusing on panel estimation and long-horizon forecasts.

Antinucleus Production at RHIC

Light antinuclei may be formed in relativistic heavy ion collisions via final state coalescence of antinucleons. The yields of antinuclei are sensitive to primordial antinucleon production, the volume of the system at kinetic freeze-out, and space-momentum correlations among antinucleons at freeze-out. We report here preliminary STAR results on antideuteron and antihelion production in 130A GeV Au+Au collisions. These results are examined in a coalescence framework to elucidate the space-time structure of the antinucleon source.Comment: 4 pages, 3 figures, talk given at Quark Matter 200

Feasibility Test of the MedaCube

Poor adherence is a significant barrier to achieve better patient outcomes. Rates of non-adherence approach 40% resulting in 10% of all emergency department visits and 23% of admissions into skilled nursing facilities. Many factors contribute to medication non-adherence including psychological and memory disorders, aging and pill burden. The MedaCube is a medication management system intended to help solve unintentional medication non-adherence. The device is designed to dispense scheduled and as-needed oral medications. The MedaCube provides audio and visual prompts alerting subjects to administer their medications. Caregivers receive notification of missed doses, late doses and refill requests. The null hypothesis is that use of the MedaCube results in no difference in medication adherence when compared with six month prior adherence in individual subjects

An Economic Analysis of Carbon Sequestration for Wheat and Grain Sorghum Production in Kansas

This study examined the economic potential with and without carbon credit payments of two crop and tillage systems in South Central Kansas that could reduce carbon dioxide emissions and sequester carbon in the soil. Experiment station cropping practices, yield data, and soil carbon data for continuously cropped wheat and grain sorghum produced with conventional tillage and no-tillage from1986 to 1995 were used to determine soil carbon changes and to develop enterprise budgets to determine expected net returns for a typical dryland farm in South Central Kansas. No-till had lower net returns because of lower yields and higher overall costs. Both crops produced under no-till had higher annual soil C gains than under conventional tillage. Carbon credit payments may be critical to induce farm managers to use cropping practices, such as no-till, that sequester soil carbon. The carbon credit payments needed will be highly dependent on cropping system production costs, especially herbicide costs, which substitute for tillage as a means of weed control. The C values estimated in this study that would provide an incentive to adopt no-tillage range from $0 to$95.991ton/year, depending upon the assumption about herbicide costs. In addition, if producers were compensated for other environmental benefits associated with no-till, carbon credits could be reduced.carbon credit value, carbon sequestration, grain sorghum, no-tillage, wheat, Crop Production/Industries,

Derived Carbon Credit Values for Carbon Sequestration: Do CO2 Emissions From Production Inputs Matter?

Environmental Economics and Policy,

DERIVED CARBON CREDIT VALUES FOR CARBON SEQUESTRATION: DO CO2 EMISSIONS FROM PRODUCTION INPUTS MATTER ?

An economic analysis was conducted involving wheat and grain sorghum production systems that affect carbon dioxide emissions and sequester soil carbon. Parameters examined were expected net returns, changes in net carbon sequestered and the value of carbon credits necessary to equate net returns from systems that sequester more carbon to those that sequester less with and without adjustments for CO2 emissions from production inputs. Evaluations were based on experiment station cropping practices, yield, and soil carbon data for continuously cropped and rotated wheat and grain sorghum produced with conventional and no-tillage. No-till had lower net returns because of lower yields and higher overall costs. Both crops produced under no-till had higher annual soil C gains than under conventional tillage. However, no-till systems had higher total atmospheric emissions of C from production inputs. The differences were relatively small. The C values estimated in this study that would equate net returns of no-tillage to conventional tillage range from $7.82 to$58.69/ton/yr when C emissions from production inputs were subtracted from soil carbon sequestered and $7.79 to$54.99/ton/yr when atmospheric emissions were not considered.Environmental Economics and Policy,

Exploiting Machine Learning to Subvert Your Spam Filter

Using statistical machine learning for making security decisions introduces new vulnerabilities in large scale systems. This paper shows how an adversary can exploit statistical machine learning, as used in the SpamBayes spam filter, to render it useless—even if the adversary’s access is limited to only 1 % of the training messages. We further demonstrate a new class of focused attacks that successfully prevent victims from receiving specific email messages. Finally, we introduce two new types of defenses against these attacks.

Three Numerical Puzzles and the Top Quark's Chiral Weak-Moment

Versus the standard model's t --> W b decay helicity amplitudes, three numerical puzzles occur at the 0.1 % level when one considers the amplitudes in the case of an additional (f_M + f_E) coupling of relative strength 53 GeV. The puzzles are theoretical ones which involve the t --> W b decay helicity amplitudes in the two cases, the relative strength of this additional coupling, and the observed masses of these three particles. A deeper analytic realization is obtained for two of them. Equivalent realizations are given for the remaining one. An empirical consequence of these analytic realizations is that it is important to search for effects of a large chiral weak-moment of the top-quark, the effective mass-scale is about 53 GeV. A full theoretical resolution would include relating the origin of such a chiral weak-moment and the mass generation of the top-quark, the W-boson, and probably the b-quark.Comment: 18 pages, 1 postscript table (revised to better explain notation, model #1, add a little material...