2,328,158 research outputs found

    A Note on Adapting Propensity Score Matching and Selection Models to Choice Based Samples

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    The probability of selection into treatment plays an important role in matching and selection models. However, this probability can often not be consistently estimated, because of choice-based sampling designs with unknown sampling weights. This note establishes that the selection and matching procedures can be implemented using propensity scores fit on choice-based samples with misspecified weights, because the odds ratio of the propensity score fit on the choice-based sample is monotonically related to the odds ratio of the true propensity scores.choice-based sampling, matching models, propensity scores, selection models

    Fit and the system theory of control

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    In this article we discuss freedom of choice in action and its relationship with the concepts of fit and effectiveness from a managerial point of view and using a designing perspective. We have give our perspectives on fit as a construction, on freedom of choice and on dynamics. We regard the traditional interpretation of fit as static and deterministic and continued ideas of Thompson, Donaldson en Gresov & Drazin. The Systems Theory of Control does offer ways to gain more insight into theories about fit. A new dynamic concept does offer a conceptual framework for determining whether the actions at t1 and t2 may lead to results at t3. The levels of aggregation were 1 2 3 introduced for analytical purposes mainly. This advances the discussion about freedom of choice in action and fit and effectiveness by a small step.

    Influence of electrode geometry and NLLS fit analysis of I-V measurements in a three-electrode cell

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    The analysis of electrode polarisation (I-V) measurements of oxygen electrodes on δ-Bi2O3-based solid electrolytes is complicated by an ohmic polarisation correction which is of the order of the electrode resistance. The analysis can be performed with a NLLS fit technique, which includes this correction resistance, Ru, as adjustable parameter. By an appropriate choice of the electrode geometry the factor Ru can be minimized

    Empirical Tests of Intransitivity Predicted by Models of Risky Choice

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    Recently proposed models of risky choice imply systematic violations of transitivity of preference. Five studies explored whether people show patterns of intransitivity predicted by four descriptive models. To distinguish ?true? violations from those produced by ?error,? a model was fit in which each choice can have a different error rate and each person can have a different pattern of true preferences that need not be transitive. Error rate for a choice is estimated from preference reversals between repeated presentations of the same choice. Results of five studies showed that very few people repeated intransitive patterns. We can retain the hypothesis that transitivity best describes the data of the vast majority of participants. --decision making,errors,gambling effect,reference points,regret,transitivity

    An updated analysis of NN elastic scattering data to 1.6 GeV

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    An energy-dependent and set of single-energy partial-wave analyses of NNNN elastic scattering data have been completed. The fit to 1.6~GeV has been supplemented with a low-energy analysis to 400 MeV. Using the low-energy fit, we study the sensitivity of our analysis to the choice of πNN\pi NN coupling constant. We also comment on the possibility of fitting npnp data alone. These results are compared with those found in the recent Nijmegen analyses. (Figures may be obtained from the authors upon request.)Comment: 17 pages of text, VPI-CAPS-7/

    Dark Energy or Apparent Acceleration Due to a Relativistic Cosmological Model More Complex than FLRW?

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    We use the Szekeres inhomogeneous relativistic models in order to fit supernova combined data sets. We show that with a choice of the spatial curvature function that is guided by current observations, the models fit the supernova data almost as well as the LCDM model without requiring a dark energy component. The Szekeres models were originally derived as an exact solution to Einstein's equations with a general metric that has no symmetries and are regarded as good candidates to model the true lumpy universe that we observe. The null geodesics in these models are not radial. The best fit model found is also consistent with the requirement of spatial flatness at CMB scales. The first results presented here seem to encourage further investigations of apparent acceleration using various inhomogeneous models and other constraints from CMB and large structure need to be explored next.Comment: 6 pages, 1 figure, matches version published in PR

    Which governs - the relationship or the contract?

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    According to the transaction cost economics literature, a firm’s external contractual relationships must be ‘fit for purpose’. What is a ‘fit for purpose’ contractual relationship should not be a normative decision, but an objective one, to be made with regard to achieving transaction cost efficiency, while defending the core competencies of the firm. Data from a Hong Kong case study is used to examine whether or not the client’s choice of contractual relationship is ‘fit for purpose’ and also to evaluate the impact of such a choice. The findings suggest that maintaining a relationship of high quality as a strategic policy not only reduces recourse to the contract but, also improves the quality and predictability of project performance and, is an antidote to ill-aligned contractual elements. These findings lend support to the growing trend towards relationship or relational contracting in construction

    Analyzing loss aversion and diminishing sensitivity in a freight transport stated choice experiment

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    Choice behaviour might be determined by asymmetric preferences whether the consumers are faced with gains or losses. This paper investigates loss aversion and diminishing sensitivity, and analyzes their implications on willingness to pay and willingness to accept measures in a reference pivoted choice experiment in a freight transport framework. The results suggest a significant model fit improvement when preferences are treated as asymmetric, proving both loss aversion and diminishing sensitivity. The implications on willingness to pay and willingness to accept indicators are particular relevant showing a remarkable difference between symmetric and asymmetric model specifications. Not accounting for loss aversion and diminishing sensitivity, when present, produces misleading results and might affect significantly the policy decisions.freight transport, choice experiments, willingness to pay, preference asymmetry
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