关键词： Reverse mortgage   Early selling of house   Optimal decision   Random death time   Stochastic housing Price  

摘要： Reverse mortgage (RM) borrowers may get benefit from terminating the contract by selling their house early. For analyzing the termination rate, the authors investigate the rules that govern an elder's decision to sell a house early. The decision is found to be influenced by the strength of the elder's desire to stay in the home, the uncertainty of the elder's death time, and the stochastic price of the house. To more thoroughly elucidate changes in the probability of a sale over time, the authors provide an example illustrating how one can use this decision rule to calculate the probability distribution for selling a house early. Sensitivity analyses are provided to show the influence of the model's parameters on this distribution. Evidence that the model estimates the termination rate more accurately than the traditional model is also provided. The authors' investigation should not only help RM lenders better understand the RM borrower's decision-making process but also help them accurately estimate the RM's termination rate.

关键词： Cost-effectiveness analysis   Errors   Modeling   Health technology assessment   Economic models   Validation  

摘要： Background Economic models play a central role in the decision-making process of the National Institute for Health and Care Excellence (NICE). Inadequate validation methods allow for errors to be included in economic models. These errors may alter the final recommendations and have a significant impact on outcomes for stakeholders. Objective To describe the patterns of technical errors found in NICE submissions and to provide an insight into the validation exercises carried out by the companies prior to submission. Methods All forty-one single technology appraisals (STAs) completed in 2017 by NICE were reviewed and all were on medicines. The frequency of errors and information on their type, magnitude, and impact was extracted from publicly available NICE documentation along with the details of model validation methods used. Results Two STAs (5 percent) had no reported errors, nineteen (46 percent) had between one and four errors, sixteen (39 percent) had between five and nine errors, and four (10 percent) had more than ten errors. The most common errors were transcription errors (29 percent), logic errors (29 percent), and computational errors (25 percent). All STAs went through at least one type of validation. Moreover, errors that were notable enough were reported in the final appraisal document (FAD) in eight (20 percent) of the STAs assessed but each of these eight STAs received positive recommendations. Conclusions Technical errors are common in the economic models submitted to NICE. Some errors were considered important enough to be reported in the FAD. Improvements are needed in the model development process to ensure technical errors are kept to a minimum.

关键词： Nonlinear model predictive control   Economic model predictive control   Dynamic real time optimization   Periodic optimal control   Changing economic criteria  

摘要： In this paper, we consider the problem of periodic optimal control of nonlinear systems subject to online changing and periodically time-varying economic performance measures using model predictive control (MPC). The proposed economic MPC scheme uses an online optimized artificial periodic orbit to ensure recursive feasibility and constraint satisfaction despite unpredictable changes in the economic performance index. We demonstrate that the direct extension of existing methods to periodic orbits does not necessarily yield the desirable closed-loop economic performance. Instead, we carefully revise the constraints on the artificial trajectory, which ensures that the closed-loop average performance is no worse than a locally optimal periodic orbit. In the special case that the prediction horizon is set to zero, the proposed scheme is a modified version of recent publications using periodicity constraints, with the important difference that the resulting closed loop has more degrees of freedom which are vital to ensure convergence to an optimal periodic orbit. In addition, we detail a tailored offline computation of suitable terminal ingredients, which are both theoretically and practically beneficial for closed-loop performance improvement. Finally, we demonstrate the practicality and performance improvements of the proposed approach on benchmark examples. (C) 2020 Elsevier Ltd. All rights reserved.

关键词： Experience economy   revisit intention   satisfaction   theme park  

摘要： Although the success of a theme park depends heavily on visitors' experience, few studies have sought to understand visitor behaviors. This research employs the experience economy model to investigate how different types of experience influence visitors' satisfaction with the theme park and intention to revisit. A structural equation modeling approach with 530 visitors showed that both educational and esthetic experiences in theme parks significantly influenced visitors' satisfaction while escapism was the only important experience that led to intention to revisit. This study offers a conceptual and specific perspective for understanding the various experiences available to a visitor and their separate impacts on satisfaction and intention to revisit. Findings provide concrete suggestions for developing effective programs and promotional materials, which in turn will help theme park operators to enhance their offerings and services and enrich visitors' experiences.

关键词： 水资源管理   经济模型   水资源生态   生态文明制度   管理职责   生态系统   自然资源   水文物理  

摘要： 水资源是构成生态系统的重要元素,也是人类生存不可缺少的自然资源。目前我国正大力建设生态文明制度,国家政府积极加强对自然资源的管理,其中对水资源的管理制度进行了深入改革。本文从管理体制和管理制度制度两方面全方位分析当前我国针对水资源的管理现状,认为当前我国水资源管理存在着管理职责漏洞、水资源相关制度不完善、缺乏水资源生态功能管理等主要问题。从水文物理经济模型、概念性经济模型和系统理论经济模型三个角度分析了基于水文经济模型的水资源管理方法,并加以实验论证,实验结果表明,引入水文经济模型后,水资源管理方法更好。

关键词： 中国金融出版社   投入产出模型   CGE模型   经济模型   潜在产出   VAR模型   新书推荐   联立方程模型  

摘要： 本书介绍了我国投入产出模型、联立方程模型、CGE模型、潜在产出模型、VAR模型及先行指标体系的开发和应用方面的详细情况,从实务出发,注重模型的应用,总结了调查统计司多年来在经济模型开发和应用方面的实践经验,介绍了一些解决建模问题的方法,具有很高的实用价值,可供相关学者和分析人员参考。

关键词： Contracts   Public transport   Concessions   Bus operators   Incentives   Economic modelling  

摘要： In many large cities worldwide, private companies operate public transport systems under concession contracts granted by the local governments. The performance of these concessions, including the quality of service and amount of subsidy, is often an issue of public debate. In this context, a major factor that determines performance is the concession contract. Payment mechanisms (established in the contract) influence the operator's decisions by providing certain incentives. Therefore, it is important to study the effects of the payment mechanism on the performance of the transport system. In this study, we examine payment schemes that are linear in the frequency of transport services and number of passengers transported;moreover we compare the impact on operators' decisions by incorporating a contract design analysis in the micmeconomic modelling. These effects are analysed in terms of operational variables and social welfare, including benefits for reducing externalities. To conduct this analysis, we formulate a microeconomic model and perform numerical simulations. The results show that the payment made per frequency plays an important role in the operator's decision making, that is, the regulator can use this payment as an incentive to modify the service decisions and achieve maximum social welfare. The model also indicates that the per-passenger payment system is an incentive to transport passengers, but after reaching a certain value its increase does not influence the operation of the service. These results may contribute to the discussion on how to design contracts to provide certain incentives.

关键词： water pricing   water management   water policy   water-use efficiency   economic model   inter-sectoral   river basin  

摘要： This study describes an economic model in the Guadalquivir river basin (Southern Spain) that considers inter-sectoral and hydrological effects of changes in water use as a response to various water-pricing policy scenarios. The main economic variables include water use, gross regional product, return flows in the river basin, and employment at sectoral and basin levels. The response of the different sectors to water pricing and of the sectoral productivity is derived from official data. The background of the model is based on previous research for the implementation of the UN System of Environmental-Economic Accounts and on the application of this framework to the Guadalquivir basin. Results based on the elicited curves illustrate that the structure of the demand function for irrigated agriculture passes from inelastic to elastic sections, while the function corresponding to the remaining economic sectors shows a continuous decreasing function with minor change in the elasticity structure of the curve. Results show that the impact of extreme measures of water pricing reduces water abstraction by up to 42% vs. the baseline scenario, with an economic reduction in regional Gross Domestic Product (GDP) of 1%.

关键词： Control   economic costs   economic model predictive control   optimization   peak charges  

摘要： With the increasing prevalence of variable-supply electricity production, dynamic market structures, including time-varying prices and/or peak demand charges are becoming more common for electricity consumers. This framework requires consumers to consider both the time-varying amount of electricity (i.e., energy) consumed throughout the day as well as the maximum rate of electricity purchase (i.e., power) over a given period, typically a month. Because of this complexity, online optimization techniques such as economic model predictive control (MPC) are a natural tool for consumers to use to minimize cost. However, while closed-loop optimization of these pricing structures is already being proposed for various applications, little has been established about stability or performance properties of the closed-loop system. Due in particular to the peak penalty (which violates the principle of optimality if naively included in the objective function), this theoretical gap leaves the potential for pathological closed-loop behavior despite high-quality open-loop solutions. In this paper, we derive asymptotic performance and stability results for general time-varying economic MPC. We then present a novel extended-state formulation to convert peak demand charges into a time-varying stage cost that can be optimized using economic MPC. In addition, we give a terminal cost and constraint for the augmented system that avoids reducing the feasible set in the original space. Finally, we demonstrate these structures and the closed-loop properties that they satisfy via two illustrative examples.

摘要： Objective The aim of this systematic review was to provide a comprehensive and detailed review of structural and methodological assumptions in model-based cost-effectiveness analyses of systemic metastatic colorectal cancer (mCRC) treatments, and discuss their potential impact on health economic outcome estimates. Methods Five databases (EMBASE, MEDLINE, Cochrane Library, Health Technology Assessment and National Health Service Health Economic Evaluation Database) were searched on 26 August 2019 for model-based full health economic evaluations of systemic mCRC treatment using a combination of free-text terms and subject headings. Full-text publications in English were eligible for inclusion if they were published in or after the year 2000. The Consolidated Health Economic Evaluation Reporting Standards checklist was used to assess the reporting quality of included publications. Study selection, appraisal and data extraction were performed by two reviewers independently. Results The search yielded 1418 publications, of which 54 were included, representing 51 unique studies. Most studies focused on first-line treatment (n = 29, 57%), followed by third-line treatment (n = 13, 25%). Model structures were health-state driven (n = 27, 53%), treatment driven (n = 19, 37%), or a combination (n = 5, 10%). Cohort-level state-transition modelling (STM) was the most common technique (n = 33, 65%), followed by patient-level STM and partitioned survival analysis (both n = 6, 12%). Only 15 studies (29%) reported some sort of model validation. Health economic outcomes for specific strategies differed substantially between studies. For example, survival following first-line treatment with fluorouracil, leucovorin and oxaliplatin ranged from 1.21 to 7.33 years, with treatment costs ranging from US$8125 to US$126,606. Conclusions Model-based cost-effectiveness analyses of systemic mCRC treatments have adopted varied modelling methods and structures, resulting in substantially differen