Time inconsistency and retirement planning

We quantify the welfare gains from better retirement planning using a model in which retirement planning is time inconsistent. A modest increase in a household’s planning horizon by just a few years generates large aggregate and individual welfare gains.     

An inventory model with variable demand,component cost and selling price for deteriorating items

In this paper, we develop an economic order quantity (EOQ) model for finite production rate and deteriorating items with time dependent increasing demand. The component cost and the selling price are considered at a continuous rate of time. The objective of this model is to maximize the total profit over the finite planning horizon. We also want to find the integral number of orders in the finite planning horizon. A numerical example, graphical representations and sensitivity analysis are given to illustrate the model.     

On the timing of information release

We consider a simple principal-agent model in which moral hazard concerns can make it attractive to delay the release of valuable planning information. We also demonstrate that temporary manipulation of the content of the information released can be valuable.     

A dynamic model of firm behavior in a planned economy

Conclusion This paper presents a dynamic model of the interaction between the planning authority and a firm in a centrally planned economy with emphasis on the firm's decision-making process and its results, given the overall constraints imposed by the planners. For possible relationships between the actual and target levels of output over time, the model offers either the case of an initial period of under-fulfillment followed by a period of overfulfillment or the case of continuous overfulfillment. We have also determined how a firm reacts to the planning authority changing one of its overall constraints (the final target or the length of the time period) or one of the parameters of the firm's bonus function. It is crucial for the planning authority to have a good understanding of what a firm's response to any of these changes will be in order to be able to select an optimal strategy in light of the ultimate goals of the planning mechanism. The results of our paper offer useful insights for this selection process.     

On the neoclassical growth model with non-constant discounting

We study the neoclassical growth model with non-constant discounting. We do not assume specific functional forms for discounting and demonstrate that the competitive economy always performs better than the planning economy.     

Equilibrium Welfare and Government Policy with Quasi-geometric Discounting

We consider a representative-agent equilibrium model where the consumer has quasi-geometric discounting and cannot commit to future actions. We restrict attention to a parametric class for preferences and technology and solve for time-consistent competitive equilibria globally and explicitly. We then characterize the welfare properties of competitive equilibria and compare them to that of a planning problem. The planner is a consumer representative who, without commitment but in a time-consistent way, maximizes his or her present-value utility subject to resource constraints. The competitive equilibrium results in strictly higher welfare than the planning problem whenever the discounting is not geometric. Journal of Economic Literature Classification Numbers: E21, E61, E91.     

The Revealed Preference Theory of Changing Tastes

We analyse preferences over finite decision problems in order to model decision-makers with „changing tastes”. We provide conditions on these preferences that identify the Strotz model of consistent planning. Building on an example given by Peleg and Yaari (1973) , we show that for problems with infinitely many choices, Strotz's representation of preferences may not be well defined. For that case, we propose a well-defined approximation which is empirically indistinguishable from the Strotz preference that is being approximated.     

斯坦纳生态规划模式及其对衡水湖生态建设的启示

斯坦纳的生态规划模式立足复合生态系统的结构与功能,对系统要素及其结构进行设计,实现整体人文生态系统的平衡性、和谐性和健康性。文章阐述了斯坦纳生态规划模式的11个相互影响的步骤,并从倡导生态文化、提倡公众参与和构建衡水湖生态规划适用模式三个方面,提出了对衡水湖生态建设的启示。     

基于管理熵的旅游规划情报系统评价研究

旅游规划信息资料掌握的多寡,直接关系到旅游规划成果质量的好坏。文章首先详细分析了旅游规划情报信息系统的特征,在此基础上应用旅游规划信息熵的理论,提出了旅游规划情报管理熵评价模型,最后提出了提高我国旅游规划水平的几点新思路。     

Frisch and Tinbergen on economic planning

The Frisch-Tinbergen model of central economic planning represents the first important non-Soviet planning model. This constrained optimization model makes the central planner a staff adviser to the Premier. The central planner explores the Premier's preference ordering and recommends instruments that maximize the Premier's utility, given the constraints within an econometric model. This model assumes Premiers have no preference over instruments or models and that planning agencies have neither internal structure nor operating responsibilities. The paper explores the consequences of removing such limiting assumptions, utilizing the results of more recent contributions to the theory of.-economic systems.     

城市水休闲旅游“不规则锥形”规划模型猜想

水休闲旅游规划是生态型城市发展旅游经济的创新点。如何整合区域内水利资源、合理规划和运营区域内滨水空间,如何引入生态循环式管理理念和开发规划步骤评价体系的同时确保水休闲旅游资源开发规划与生态循环经济建设协同发展是我们必须面对的课题。主要探讨城市水休闲旅游"不规则锥形"规划模型,并从城市水休闲旅游规划常规性思路剖析、规划战略理念与切实目标、模型猜想与构成因素分析、模型运行程序设计、模型困境、时空拉升理念设置这六个角度进行研究,以期更好拓展城市规划经济。     

Thinking Ahead: The Decision Problem

We propose a model of costly decision making based on time-costs of deliberating current and future decisions. We model an individual decision-maker's thinking process as a thought-experiment that takes time, and lets the decision maker 'think ahead' about future decision problems in yet unrealized states of nature. By formulating an intertemporal, state-contingent, planning problem which may involve costly deliberation in every state of nature, and by letting the decision maker deliberate ahead of the realization of a state, we attempt to capture the basic observation that individuals generally do not think through a complete action plan. Instead, individuals prioritize their thinking and leave deliberations on less important decisions to the time or event when they arise.     

Futures-oriented municipal planning

Amid the current political and economic uncertainties, the long-term perspective in municipal planning in Sweden has been shortened and planning has become more like crisis management. This paper presents a model for municipal futures studies that may contribute toward development of a municipal planning system that can adapt itself to different types of sudden change while still taking long-term welfare goals and resource conservation issues into consideration.So far, models in futures studies have been largely developed to study global and national development. The article therefore places special emphasis on the methodological issues of developing a model for municipal futures studies. The aim of the model is to increase strategic thinking by planners and decision-makers; it requires that futures studies and conventional planning activities be closely integrated.The model is in the process of implementation in the municipality of Västerås. Some features of the model will also be integrated into a futures study of urban housing to be undertaken in the municipality of Umeå.     

Probabilistic representation of complexity

We introduce a framework to study individuals’ behavior in environments that are deterministic, but too complex to permit tractable deterministic representations. An agent in these environments uses a probabilistic model to cope with his inability to think through all contingencies in advance. We interpret this probabilistic model as embodying all patterns the agent perceives, yet allowing for the possibility that there may be important details he had missed. Although the implied behavior is rational, it is consistent with an agent who believes his environment is too complex to warrant precise planning, foregoes finely detailed contingent rules in favor of vaguer plans, and expresses a preference for flexibility.     

The fragility of a discipline when a model has monopoly status

We consider the consequences of a scientific literature with only one model of an important phenomenon. The falsification of the model would mean falsification of the science. Scientists who would prefer not to have their discipline falsified will be tempted to find ad hoc explanations to excuse the failure. To test this hypothesis we propose a study of the economic forecasts of the comparative Soviet and American growth rates in the years before a public choice model of central planning was a viable alternative to the public interest model. JEL Code A11, B23 Earlier versions of the paper were presented at the University of Manitoba Economics Department Retreat in October 2005 and at the Center for Study of Public Choice Wednesday Seminar in November 2005. We thank the participants for their suggestions. All the remaining errors are our responsibility.     

距离测度视角下生态城市规划方案三维评价模型研究

在高速发展的城镇化和节能环保要求的双重背景下,生态城市成为中国城镇化发展的首选,各级政府短期内推出了大量生态城市规划方案,但多数生态城市规划方案存在随意性和主观性等问题。对生态城市规划方案、规划方案运作机制和规划方案保障措施3个维度进行了系统分析,通过指标选取构建了生态城市规划三维评价模型,采用距离测度方法对方案进行了综合排序,采用“四方格评价屏幕”方法对方案进行了投影分析。通过对中国深圳、重庆、潍坊三地的生态城市规划方案进行评价,结果显示,该模型可以有效地对生态城市规划方案进行综合评价,并根据评价结果提出针对性的优化建议,有助于降低生态城市规划实践的制度成本和社会成本。     

Productivity paralysis and the complexity problem: Why do centrally planned economies become prematurely gray?

We develop a theory of the Soviet productivity growth slowdown that attributes it to difficulties encountered by systems of central planning as the economy becomes more complex. Shortages become more disruptive as the economy modernizes, forcing the economy to operate at an increasing distance from its production possibility frontier. The model also supports the widely held notion that consumer welfare suffers in Soviet-type economies as consumers' needs become increasingly sophisticated.     

Whom to send to Doha? The shortsighted ones!

Analyses of the effects of trade policies focus on comparisons of two different steady states, restricting the investigation to the long run. In order to account for the adjustments and to capture the relevant transmission mechanisms of changes in trade costs, such as market size, entry and exit, as well as productivity changes of firms, we base our trade policy analysis on a dynamic new trade theory model. This approach has two advantages. (i) It allows us to take account of the transitional process after a change in tariffs. (ii) It allows us to take account of the shortsightedness of policy makers. We show that Nash-equilibrium tariffs based on a dynamic trade model are lower than Nash-equilibrium tariffs based on a static model. We also show that shortsighted politicians tend to set lower tariffs than politicians with a longer planning horizon.     

Retirement planning in the light of changing demographics

With increasing longevity and decreasing fertility rates, governments and policy makers are increasingly engaged in the question of long term retirement planning. In many cases this has included emphasising the need for individuals to take more responsibility for their own retirement planning through tax incentives, compulsion and changes to the age at which state retirement benefits become available. In the case of Australia, as is considered here, long term retirement planning has been focused around the development of a compulsory defined contribution (DC) superannuation system. Here we investigate the interaction between population ageing and the sustainability of the superannuation system by modelling a general superannuation scheme to compare the adequacy of retirement funds under a number of alternative scenarios. The model incorporates stochastic longevity forecasts and provides insight into the sufficiency of compulsory retirement saving both now and future. We find that the current pension scheme is more robust to longevity improvements for mid-class individuals however significant gaps arise for low-income individuals as longevity improves. Without addressing these issues, government expenditure is expected to increase substantially.     

资源型城市农业产业空间布局实证研究

分析了资源型城市平顶山市的农业产业空间布局存在的问题,从农业产业空间布局整合的可行性研究入手,通过极核模式、点—轴模式及圈层模式的分析,提出了"八点、五轴"的农业产业空间布局整合模式,构建平顶山市郊农业区为极核、县郊农业区为一级节点的点轴模式。根据农业生产环境条件和农业产业用地的空间分布特征,规划布局了三个农业圈,构筑科技核心区、农产品配售区、农产品生产加工腹地区三圈组合的农业产业空间开发结构。资源型城市农业产业空间布局研究能够促使农业产业的发展,使农业成为资源型城市的重要产业支撑,推进资源型城市平稳经济转型。