Continuous Choice Research Articles

Does Patients' Perception Affect Self-Care Practices? The Perspective of Health Belief Model.

BackgroundPoor lifestyle choices contribute to the continued growth of chronic illness and disability. Patients with diabetes require continuous self-care choices and management to minimize the short- and long-term impact of the disease. This study aimed at assessing the use of the health belief model to describe self-care practices among patients with diabetes.MethodsAn institutional-based cross-sectional study was conducted from February to March 2019 in Gondar City, Northwest Ethiopia. A total of 396 diabetics patients were selected using a systematic random sampling technique. Pretested, structured, and interview administered questionnaire was used for data collection. The collected data were analyzed using STATA 14. Bivariate and multivariate logistic regression models were fitted to identify the factors associated with self-care behavior. Adjusted odds ratio (AOR) with 95% confidence interval (CI) and p-values <0.05 were used to declare statistical association.ResultsHealth belief model described 48% of the variance in self-care practices of patients with diabetes. More than half (55.6%) of diabetic patients had good self-care practice. Of the participants, 45.8% and 49.9% had low perceived susceptibility and perceived severity, respectively. The strongest correlation was found between cues to action and perceived severity of health belief model constructs (P<0.001). Formal education, longer duration of diabetes, high social support, high perceived severity, and high self-efficacy contributed to good self-care practices, whereas comorbidities, high perceived benefit, and high perceived barrier were associated with poor self-care practices.ConclusionSelf-care practice of diabetes patients in Gondar City was considerably low. Health professionals need to strengthen delivering tailored health messages on the benefit self-care practices and means of overcoming the potential barriers. Health communication programs are also better to consider for individuals with comorbidities, lack of social support, and lower education.

Sobolev Lifting over Invariants

We prove lifting theorems for complex representations $V$ of finite groups $G$. Let $\sigma=(\sigma_1,\dots,\sigma_n)$ be a minimal system of homogeneous basic invariants and let $d$ be their maximal degree. We prove that any continuous map $\overline{f} \colon {\mathbb R}^m \to V$ such that $f = \sigma \circ \overline{f}$ is of class $C^{d-1,1}$ is locally of Sobolev class $W^{1,p}$ for all $1 \le p<d/(d-1)$. In the case $m=1$ there always exists a continuous choice $\overline{f}$ for given $f\colon {\mathbb R} \to \sigma(V) \subseteq {\mathbb C}^n$. We give uniform bounds for the $W^{1,p}$-norm of $\overline{f}$ in terms of the $C^{d-1,1}$-norm of $f$. The result is optimal: in general a lifting $\overline{f}$ cannot have a higher Sobolev regularity and it even might not have bounded variation if $f$ is in a larger H\"older class.

A new closed form multiple discrete-continuous extreme value (MDCEV) choice model with multiple linear constraints

Traditional multiple-discrete continuous choice models that have been formulated and applied in recent years consider a single linear resource constraint, which, when combined with consumer preferences, determines the optimal consumption point. However, in reality, consumers may face multiple resource constraints, such as those associated with time, money, and storage capacity. Ignoring such multiple constraints and instead using a single constraint can, and in general will, lead to poor data fit and inconsistent preference estimation, which can then have a serious negative downstream effect on forecasting and welfare/policy analysis. Unlike earlier attempts to address this multiple constraint situation, we formulate a new multiple-constraint (MC) multiple discrete continuous extreme value (MDCEV) model (or the MC-MDCEV model) that retains a closed-form probability structure and is as simple to estimate as the MDCEV model with one constraint. We achieve this by assuming a type-I extreme value distribution for the error term in its minimization form in the baseline utility preference of each good rather than a maximization form as in Bhat's (2005; 2008) original MDCEV formulation. The statistical foundation of the proposed model is based on the fact that the difference between a minimal type-I extreme value random variable with scale σ and the weighted sum of the exponential of standardized minimal type-I extreme value random variables (scaled up by σ) leads to an apparently new multivariate distribution that has an elegant and closed-form survival distribution function. Results from a simulation experiment show that our proposed model substantially outperforms single-constraint models; the results also highlight the serious mis-estimation that is likely to occur if only a subset of active constraints is used. The proposed model is applied to a case of week-long activity participation where individuals are assumed to maximize their utility from time-use subject to time and money budgets.It is hoped that our proposed simple closed-form multi-constraint MDCEV model will contribute to a new direction of application possibilities and to new research into situations where consumers face multiple constraints within a multiple discrete-continuous choice context.

Identification of firms’ beliefs in structural models of market competition

AbstractFirms make decisions under uncertainty and differ in their ability to collect and process information. As a result, in changing environments, firms have heterogeneous beliefs on the behaviour of other firms. This heterogeneity in beliefs can have important implications on market outcomes, efficiency and welfare. This paper studies the identification of firms’ beliefs using their observed actions—a revealed preference and beliefs approach. I consider a general structural model of market competition where firms have incomplete information and their beliefs and profits are nonparametric functions of decisions and state variables. Beliefs may be out of equilibrium. The framework applies both to continuous and discrete choice games and includes as particular cases models of competition in prices or quantities, auction models, entry games and dynamic games of investment decisions. I focus on identification results that exploit an exclusion restriction that naturally appears in models of competition: an observable variable that affects a firm's cost (or revenue) but does not have a direct effect on other firms’ profits. I present identification results under three scenarios—common in empirical industrial organization—on the data available to the researcher.

Climate Finance and Emission Reductions: What Do the Last Twenty Years Tell Us?

In the framework of the Paris Agreement implementation, financial transfers remain a major point of negotiation for addressing equity concerns raised by the ambitious climate objectives. In complement to the theoretical, experimental and numerical studies that have examined the role of transfers in facilitating coalitions, we conduct the first empirical analysis of their impact on national carbon emission reductions. We build on the existing literature to develop a conceptual framework which models continuous national emission choices in the presence of financial transfers. We infer an equation of the impact of mitigation and adaptation finance on national emissions of recipient countries. We test the derived hypothesis using carbon emissions data of non-OECD countries in the last 20 years. We find that public adaptation and mitigation finance tend to increase emissions. Private mitigation finance seems to reduce them only after five years following the transfers.

A multiple discrete continuous model of time use that accommodates non-additively separable utility functions along with time and monetary budget constraints

This paper proposes a multiple discrete continuous (MDC) choice modelling framework with the following features for analyzing individuals’ time use decisions: (a) accommodates non-additively separable (NAS) utility functions with respect to time allocation across different non-work activities, (b) considers both time and money constraints by integrating the two constraints into a single economic constraint, and (c) allows corner solutions for (i.e., non-participation in) discretionary, non-work activities. The proposed framework is applied to analyze weekly time use of employed individuals in Netherlands using a data set derived from the Time use and Consumption survey of the Longitudinal Internet Studies for the Social Sciences (LISS) panel. The empirical results of the proposed model are compared to those from two simpler models – (a) a model that ignores the monetary budget constraint but employs the NAS utility function and (b) a model that considers both time and money budget constraints but uses a simpler, additively separable utility function. The results suggest that considering both time and money constraints, when combined with the NAS utility function, facilitates in capturing rich substitution patterns in time allocation to non-work activities, in addition to revealing demographic heterogeneity in satiation effects. Further, the proposed model offers a superior goodness of fit when compared to that from the simpler models that ignore either the monetary constraint or the NAS utility function. Finally, the model results provide important policy insights for reducing demographic inequities in time allocation among employed individuals.

Chemotherapy-based split stereotactic body radiation therapy for borderline resectable and locally advanced pancreatic cancer: study protocol of a prospective, single-arm phase II trial

IntroductionThe question of how to administer adequate chemotherapy to synchronise stereotactic body radiation therapy (SBRT) treatment strategy to maximise the benefits of neoadjuvant therapy for the improved prognosis of patients...

Discrete Rent-Seeking Games with an Application to Evidence Production

Evidence production at trial, the accumulation of patents in a technological race, and lobbying are contests that often involve strategic choices over a discrete set of options. The literature has primarily focused on games with continuous effort choices. We fill this gap by studying a rent-seeking game with discrete effort choices and, for a significant class of games, derive a transformation rule that allows one to find the equilibrium of the discrete game from the equilibrium of the continuous game, which is much simpler to identify. We also discuss the limits of this approach and how well the continuous game approximates the discrete one.

Defining the Conditions of Forming Students Motivation to Movement Activity

The purpose of our study was to determine the level of motor activity in students, as well as to promote the formation of motivation to engage in physical sports. University students (n= 54, age 17-21 years) divided into 2 groups according to physical activity and sex. For the research, the self-developed questionnaire was used and processed by the statistical method with determining the relative parity indexes. The results of the research allowed studying the student's attitude to physical education in universities and independently, to assess the subjective state of health of different grade students, the reasons for abandoning physical exercises. The results are consistent with satisfaction with classes at university and the reasons for abandoning additional classes. Girls prefer classes of non-traditional types of PE that are not included in the program of the higher educational institutions and require significant financial investments that students cannot afford. Male students prefer sports games, and although they are included in the program, there are no free sections. Students pay little attention to physical activity, thus they do not have the formed need for independent exercises in physical culture, and most of them prefer to be engaged in non-traditional health-improving forms of physical culture. The amount of motor activity physical education classes showed a clear training effect and can be considered as one of the benchmarks of the compensatory role of classes in eliminating hypodynamic. Also in the article, the authors consider motivation as a dynamic process of continuous choice and decision-making, based on weighing behavioral alternatives, explaining the purposefulness, organization, and sustainability of holistic measures to achieve a certain goal acts as an incentive to act with a certain motive.

A discriminated rapid-acquisition laboratory procedure for human continuous choice.

Previous continuous choice laboratory procedures for human participants are either prohibitively time-intensive or result in inadequate fits of the generalized matching law (GML). We developed a rapid-acquisition laboratory procedure (Procedure for Rapidly Establishing Steady-State Behavior, or PRESS-B) for studying human continuous choice that reduces participant burden and produces data that is well-described by the GML. To test the procedure, 27 human participants were exposed to 9 independent concurrent random-interval random-interval reinforcement schedules over the course of a single, 37-min session. Fits of the GML to the participants' data accounted for large proportions of variance (median R2 : 0.94), with parameter estimates that were similar to those previously found in human continuous choice studies [median a: 0.67; median log(b): -0.02]. In summary, PRESS-B generates human continuous choice behavior in the laboratory that conforms to the GML with limited experimental duration.

Estimating linearized heterogeneous agent models using panel data

We develop a method to estimate heterogeneous agent models that uses not only time series of macroeconomic aggregates, but can also incorporate micro level data (repeated cross-section or panel). The micro data may be collected at lower frequency and time-aggregated. The method is based on the linearization approach of Reiter (2009), combined with optimal state aggregation as in Reiter (2010). The model may contain decision problems with both continuous and discrete choice. Linearity of the model solution allows fast computation of second moments and likelihood. We discuss various computational devices to maximize the speed of the estimation.

Modeling and forecasting daily non-work/school activity patterns in an activity-based model using skeleton schedule constraints

Abstract A dynamic, gap-based activity scheduling model is developed for predicting out-of-home non-work/school (NWS) episodes over a day. In the developed model, work/school, and night sleep are assumed to be pre-determined, thereby providing a daily “skeleton schedule”. NWS episodes are then simultaneously generated and scheduled in the available gaps as a joint activity type and destination choice, followed by a continuous time expenditure choice. The model is built on a subset of the Transportation Tomorrow Survey (TTS) collected in the Greater Toronto and Hamilton Area (GTHA) in 2001. The developed model is validated on another sample from the TTS 2001 and is also applied to forecast individuals’ schedules for the years 2006 and 2011, for which observed TTS data are also available. This study, which is rarely conducted in the literature, examines the model’s capability to replicate the base year schedule and predict the activity patterns of the future years, which is the ultimate purpose of any travel demand model. Simulation outcomes of the three years follow similar trends to each other. Replication of the base year’s schedule is more accurate than the future years; however, there are no significant changes in the accuracy of the outcomes of the model’s application on all the three years.

Generalized Euler Equation Errors for Discrete Time Dynamic Portfolio Choice Models

The solution to dynamic portfolio choice models can be formulated in terms of a value function by the Bellman principle of optimality, which reduces the multi-period optimal policy choice problem to a sequence of one-period maximization problems. For two adjacent periods, economists compute the error of numerically obtained policies by measuring how much these policies violate the intertemporal first order conditions for the optimal policy choice problem---so-called Euler equation errors. In this paper, we derive generalized Euler equation errors for the solution to a broad class of discrete time dynamic portfolio choice models where the policies are continuous choice variables. Our key precondition is that the gradient of the value function with respect to the state variables can be approximated. This is, for example, the case when a global polynomial basis or B-spline basis functions are used for the approximation of the value function within the discrete time dynamic programming approach. We apply our theoretical results to exemplary, representative dynamic portfolio choice models.

Understanding tourists’ expenditure patterns: a stochastic frontier approach within the framework of multiple discrete–continuous choices

This article analyzes the determinants of tourists’ expenditure behavior through the joint adoption of two microeconometric approaches, namely, the Stochastic Frontier (SF) and the Multiple Discrete Continuous Extreme Value (MDCEV) model. Despite the attention that analysts have dedicated to consumers’ expenditure behavior in recent years, several limitations concerning the role of budget and the phases of money allocation are still affecting the literature on the topic. In this study, the SF is employed to identify the unobserved individual maximum level of spending allotted for a trip. Once estimated, the frontier is included as a travel budget in the utility-maximizing framework of a MDCEV model. The MDCEV approach allows to simultaneously assess two moments characterizing spending decisions. That is, the decision to allocate the budget to several expenditure categories and the decision concerning the amount to allocate to each category. Data adopted for this research is collected by the Swiss Statistical Office (UST) through a representative Household Budget Survey (Haushaltsbudgeterhebung). Data related to Swiss residents’ leisure travel expenditures are investigated; more specifically, the expenditure categories considered in the analysis are Accommodation, Transportation, Shopping and Food & Beverage.

Modeling workers’ daily out-of-home maintenance activity participation and duration

Abstract This paper applies a multiple discrete–continuous choice model to determine worker’s decisions on interdependencies of maintenance activity participation and duration over different time periods in a worker’s day. To accommodate household effect, each time period is further defined according to whether the maintenance activities were conducted independently or jointly with other household members. Using the household survey data from the New York metropolitan area, the worker’s participation and duration decisions were jointly estimated for four time periods, including the morning commute, midday, evening commute, and after evening commute. To account for the censored nature of the duration data, a “censored system of equations” proposed by Shonkwiler and Yen was adopted and modified to increase asymptotic efficiency of the parameter estimates. Despite simplicity of the model and its ease of implementation, the estimation results offer valuable insights into the effects of socio-demographics, land use density, transportation service, and work duration characteristics on worker’s daily scheduling of maintenance activities and travel in a highly urbanized environment.

Identification of Random Coefficient Latent Utility Models

This paper provides nonparametric identification results for random coefficient distributions in perturbed utility models. We cover discrete and continuous choice models. We establish identification using variation in mean quantities, and the results apply when an analyst observes aggregate demands but not whether goods are chosen together. We require exclusion restrictions and independence between random slope coefficients and random intercepts. We do not require regressors to have large supports or parametric assumptions.

Discrete‐time dynamic principal–agent models: Contraction mapping theorem and computational treatment

We consider discrete‐time dynamic principal–agent problems with continuous choice sets and potentially multiple agents. We prove the existence of a unique solution for the principal's value function only assuming continuity of the functions and compactness of the choice sets. We do this by a contraction mapping theorem and so also obtain a convergence result for the value function iteration. To numerically compute a solution for the problem, we have to solve a collection of static principal–agent problems at each iteration. As a result, in the discrete‐time setting solving the static problem is the difficult step. If the agent's expected utility is a rational function of his action, then we can transform the bi‐level optimization problem into a standard nonlinear program. The final results of our solution method are numerical approximations of the policy and value functions for the dynamic principal–agent model. We illustrate our solution method by solving variations of two prominent social planning models from the economics literature.

The Time-Domain Cell Method Is a Coupling of Two Explicit Discontinuous Galerkin Schemes With Continuous Fluxes

The cell method (CM) or discrete geometric approach (DGA) in the time domain, already introduced by Codecasa et al. in 2008 for the coupled Ampere-Maxwell and Faraday equations, is here recast as a Galerkin Method similar to the finite-element method (FEM). In particular, it is shown to be a mixed method comprising an explicit scheme and two discontinuous Galerkin (DG) FEM spaces formulated on dual meshes, in which each of the two function spaces provides a continuous numerical flux choice for its dual mesh counterpart. The implemented version is shown to compare favorably in terms of accuracy and efficiency with respect to the classic conforming FEM scheme using Whitney elements. When tested on the same tetrahedral mesh, the Courant-Friedrichs-Lewy (CFL) condition for the proposed approach is a factor of 2 less restrictive on the time step with respect to the curl-conforming FEM scheme.

The Saturation properties of Nuclear Matter Using Different Three-Body Force at zero and finite temperature

We have used the three-body force (3BF) to modify the two body forces to achieve the empirical saturation points as well as study the ground state properties for symmetric nuclear matter using the Brueckner-Hartree-Fock approximation (BHF) with the Argonne AV18 potential at zero and finite temperature. Besides the energy per nucleon (E/A) as a function of nuclear density ρ is calculated. Further, the correction of the two-body dependent potential (correction 1) is added to shift and improve the saturation properties of the nuclear matter from ρ_o=0.265 〖fm〗^(-3) to ρ_o=0.149 〖fm〗^(-3) at E/A = -16.142 MeV towards to the empirical saturation point ρ_o=0.16 〖fm〗^(-3). In addition, the pressure p for symmetric nuclear matter for zero-temperature T=0 as a function of density ρ/ρ_o using the Argonne AV18 potential is calculated revealing good agreement between our calculations and the experimental data. On other hand, more calculations for the pressure are added at different energies T= 4, 8, 12, 18 and 20 MeV. Also, the level-density parameter as a function of density ρ is calculated for the BHF approach. Moreover, the internal energy F for the symmetric nuclear matter as a function of density ρ using the Argonne AV18 potential for continuous choice at T= 4, 8, 12, 18 and 20 MeV for the BHF with and without 3BF is calculated.

The relationship between length of stay and land transportation mode in the tourism sector: A discrete–continuous framework applied to Swiss data

This study aims to investigate the relationship between travel mode and length of stay decisions in the context of domestic trips in Switzerland, formulating a discrete–continuous choice model. The adoption of this method allows us to explicitly recognize the interrelated nature of such decisions while testing and measuring the underlying correlation effects. The data source employed for the empirical analysis refers to the Household Budget Survey, which gathers information with regard to the 642 trips undertaken by Swiss resided tourists in 2010 and in particular to the most recent nonbusiness sojourn in this regard. The estimated correlation parameters reveal that tourists are likely to stay longer at the destination when travelling by train and appear to be less inclined to spend more extended sojourns when heading to the destination by car.