678 research outputs found

    EXPLAINING DISPARITIES IN THE COST OF HEALTHIER FOOD

    Get PDF
    This study examines the relative price of a standard market basket of food items and a market basket of healthier alternatives. Because people in low-income neighborhoods may have fewer grocery stores and transportation alternatives, the effects of store size and competition on the price of a market basket is estimated.Demand and Price Analysis, Food Consumption/Nutrition/Food Safety,

    THE WELFARE EFFECTS OF CONSUMING A CANCER PREVENTION DIET

    Get PDF
    This study measures the welfare changes in agriculture and to consumers should people eat the recommended levels of fruits and vegetables for a cancer prevention diet. An equilibrium displacement model is used to measure the change in welfare to fruit and vegetable industries, other commodities, and agricultural input markets.Food Consumption/Nutrition/Food Safety,

    Linkages Between Greater Fruit and Vegetable Consumption and Agriculture

    Get PDF
    This study will estimate the benefits to fruit and vegetable industries and consumers should people in the U.S. meet the USDA minimum dietary guidelines. Specifically the objectives of the study are to 1) estimate the benefits to fruit and vegetable industries and consumers should people eat the general and subgroup 7-a-day and 9-a-day recommendation; 2) estimate the benefits should smaller increases of only 10 percent or 25 percent be achieved; and 3) determine how agricultural inputs, including land and labor, would be affected by the increase in demand for fruits and vegetables. To protect against the incidence of chronic diseases such as diabetes, cardiovascular disease and cancer the 2005 USDA dietary guidelines recommend the consumption of 3 to 4 fruit servings and 4 to 5 vegetable servings a day. They also provide recommendations on the composition of fruit and vegetable consumption as well as the level. For example, almost one serving of dark leafy vegetables is recommended per day. Depite the known health benefits, many people do not eat the amounts recommended in the USDA dietary guidelines and low income consumers (those whose median household income is less than 25,000ayear)eatfewerservings.BasedontheNHANES4(Nationalhealthandnutritionexaminationsurvey)andNHANES5,averageconsumptionoffruitbylowincomeconsumerswouldneedtoincreasebyatleast83percentatmeetthe3adayrecommendationand39percentinordertomeetthe4adayrecommendation.Peopleinhigherincomehouseholdsonlyneedtoincreaseconsumptionbyonly60percentforfruitand30percentforvegetables.Theproportionalincreasesinconsumptionassumethatpeoplenolongereatpotatochipsorfrenchfriesinordertomeetdietaryguidelinesonfatconsumption.Ashiftinconsumptionpatternstotherecommendedlevelswouldcausethedemandforfruitsandvegetablestorisesignificantly,leadingtohigherpricesandincreasedproduction,shiftingtheuseofagriculturalresources(suchasland,labor,andwater)intotheproductionofthosecommodities,andbenefitingtheentireagriculturalsector.Despitethepotentialgainstoagriculture,thesevalueshavebeenignoredinpreviousstudiesofimprovednutrientintake.Suchabenefittoproducersmightjustifyadditionalpublicsectorinvestmentinpromotinghealthierdiets.Thechangesinprices,agriculturalproduction,agriculturalinputusage,andtradewillbesimulatedusinganequilibriumdisplacementmodel.Thedualapproachusedinthisanalysislaysoutbasicdemandandsupplyequationsfromdemandandcostfunctionstoshowhowequilibriumconditionschangeinresponsetoshocks,suchasanincreaseinthedemandforfruitsandvegetables.Thefunctionscharacterizethefinalmarket,allowforsubstitutabilitybetweenmarketingandnonmarketinginputsinthemarketingsector,includesthefarmsector,andchangesininputuseresultingfromchangesincropmixandsubstitutabilityinland,laborandotherinputs.Equilibriumdisplacementmodelshavebeenwidelyusedtoestimatethebenefitsofagriculturalresearchagriculturalpoliciesandthebenefitstothedairyindustryofasocialmarketingprogramtomiddleschoolchildren.Themodelisparameterizedwithfarm,marketandconsumptiondata.TheincreaseinfruitandvegetableconsumptionismodeledasashiftinthedemandcurvewiththeshiftequaltothepercentageincreaseneededtomeettheUSDAdietaryguidelines.Producersurplusisestimatedfromthechangesingrowerpricesandagriculturalproduction,lesschangesinthecostofinputs.Consumersurplusforpeoplelivinginlowincomehouseholds(lessthan25,000 a year) eat fewer servings. Based on the NHANES4 (National health and nutrition examination survey) and NHANES5, average consumption of fruit by low-income consumers would need to increase by at least 83 percent at meet the 3 a day recommendation and 39 percent in order to meet the 4 a day recommendation. People in higher-income households only need to increase consumption by only 60 percent for fruit and 30 percent for vegetables. The proportional increases in consumption assume that people no longer eat potato chips or french fries in order to meet dietary guidelines on fat consumption. A shift in consumption patterns to the recommended levels would cause the demand for fruits and vegetables to rise significantly, leading to higher prices and increased production, shifting the use of agricultural resources (such as land, labor, and water) into the production of those commodities, and benefiting the entire agricultural sector. Despite the potential gains to agriculture, these values have been ignored in previous studies of improved nutrient intake. Such a benefit to producers might justify additional public sector investment in promoting healthier diets. The changes in prices, agricultural production, agricultural input usage, and trade will be simulated using an equilibrium displacement model. The dual approach used in this analysis lays out basic demand and supply equations from demand and cost functions to show how equilibrium conditions change in response to shocks, such as an increase in the demand for fruits and vegetables. The functions characterize the final market, allow for substitutability between marketing and non-marketing inputs in the marketing sector, includes the farm sector, and changes in input use resulting from changes in crop mix and substitutability in land, labor and other inputs. Equilibrium displacement models have been widely used to estimate the benefits of agricultural research agricultural policies and the benefits to the dairy industry of a social marketing program to middle school children. The model is parameterized with farm, market and consumption data. The increase in fruit and vegetable consumption is modeled as a shift in the demand curve with the shift equal to the percentage increase needed to meet the USDA dietary guidelines. Producer surplus is estimated from the changes in grower prices and agricultural production, less changes in the cost of inputs. Consumer surplus for people living in low-income households (less than 25,000 a year median income) and higher income households is estimated from the changes in retail prices and final market quantities consumed by each income group.Food Consumption/Nutrition/Food Safety,

    Heuristics in Decision Making

    Get PDF
    Heuristics are simple rules of thumbs for problem solving that follow a logic that is quite different from consequential logic. They have long been regarded, as an inferior technique for decision making that is the source of irrational decision behavior. Recently, decision making researchers have demonstrated that some heuristics are highly efficient and can compete with complex decision models in some application domains. This paper explores the different streams of research, summarizes the state of the art decision making model, and discusses its implications for complex decisions in engineering and technology management

    Phonon-Assisted Incoherent Excitation of a Quantum Dot and its Emission Properties

    Full text link
    We present a detailed study of a phonon-assisted incoherent excitation mechanism of single quantum dots. A spectrally-detuned laser couples to a quantum dot transition by mediation of acoustic phonons, whereby excitation efficiencies up to 20 % with respect to strictly resonant excitation can be achieved at T = 9 K. Laser frequency-dependent analysis of the quantum dot intensity distinctly maps the underlying acoustic phonon bath and shows good agreement with our polaron master equation theory. An analytical solution for the photoluminescence is introduced which predicts a broadband incoherent coupling process when electron-phonon scattering is in the strong phonon coupling (polaronic) regime. Additionally, we investigate the coherence properties of the emitted light and study the impact of the relevant pump and phonon bath parameters

    Bremsstrahlung of 350--450 MeV protons as a tool to study NNNN interaction off-shell

    Get PDF
    The ppppγpp\to pp\gamma bremsstrahlung cross section is calculated within the method of coordinate space representation. It is shown that in the beam energy range of 350--450~MeV a deep attractive NN-potential with forbidden states (Moscow potential) and realistic meson exchange potentials (MEP) give rise to the cross sections that differ essentially in shape: the cross sections nearly coincide in the minima but differ by a factor of 5 approximately in the maxima. Therefore, the ppppγpp\to pp\gamma reaction at energies \sim350--450~Mev can be used to study NNNN interaction off-shell and to discriminate experimentally between MEP and Moscow potential.Comment: 5 pages, latex, 4 PS figures. Talk presented by Andrey Shirokov at the International Conference on Quark Lepton Nuclear Physics ``QULEN97'', May 20-23, 1997, Osaka, Japan; to be published in Nucl. Phys.

    Polarization fine-structure and enhanced single-photon emission of self-assembled lateral InGaAs quantum dot molecules embedded in a planar micro-cavity

    Full text link
    Single lateral InGaAs quantum dot molecules have been embedded in a planar micro-cavity in order to increase the luminescence extraction efficiency. Using a combination of metal-organic vapor phase and molecular beam epitaxy samples could be produced that exhibit a 30 times enhanced single-photon emission rate. We also show that the single-photon emission is fully switchable between two different molecular excitonic recombination energies by applying a lateral electric field. Furthermore, the presence of a polarization fine-structure splitting of the molecular neutral excitonic states is reported which leads to two polarization-split classically correlated biexciton exciton cascades. The fine-structure splitting is found to be on the order of 10 micro-eV.Comment: 14 pages, 4 figures; the following article has been submitted to Journal of Applied Physics (29th ICPS - invited paper); after it is published, it will be found at http://jap.aip.org
    corecore