EXPLICIT SOLUTIONS OF CONSUMPTION-INVESTMENT PROBLEMS IN FINANCIAL MARKETS WITH REGIME SWITCHING

We consider a consumption and investment problem where the market presents different regimes. An investor taking decisions continuously in time selects a consumption–investment policy to maximize his expected total discounted utility of consumption. The market coefficients and the investor's utility of consumption are dependent on the regime of the financial market, which is modeled by an observable finite-state continuous-time Markov chain. We obtain explicit optimal consumption and investment policies for specific HARA utility functions. We show that the optimal policy depends on the regime. We also make an economic analysis of the solutions, and show that for every investor the optimal proportion to allocate in the risky asset is greater in a "bull market" than in a "bear market." This behavior is not affected by the investor's risk preferences. On the other hand, the optimal consumption to wealth ratio depends not only on the regime, but also on the investor's risk tolerance: high risk-averse investors will consume relatively more in a "bull market" than in a "bear market," and the opposite is true for low risk-averse investors.     

The Motivation and Effectiveness of Gas Industry Economic Regulation in New South Wales, 1912–39

The oldest industry in Australia subjected to economic regulation is the gas supply industry in the state of New South Wales. In this paper the aims and motivation of the New South Wales Government in establishing the regulatory regime in 1912 and the subsequent effectiveness in achieving them are determined. Initially the regulatory regime was based on ad hoc arrangements, but eventually a more permanent structure was devised that effectively defused political controversy over gas market pricing and stabilised prices rather than substantially lowered them.     

PRICING AND HEDGING OF DERIVATIVES BASED ON NONTRADABLE UNDERLYINGS

This paper is concerned with the study of insurance related derivatives on financial markets that are based on nontradable underlyings, but are correlated with tradable assets. We calculate exponential utility‐based indifference prices, and corresponding derivative hedges. We use the fact that they can be represented in terms of solutions of forward‐backward stochastic differential equations (FBSDE) with quadratic growth generators. We derive the Markov property of such FBSDE and generalize results on the differentiability relative to the initial value of their forward components. In this case the optimal hedge can be represented by the price gradient multiplied with the correlation coefficient. This way we obtain a generalization of the classical “delta hedge” in complete markets.     

INDIFFERENCE PRICE WITH GENERAL SEMIMARTINGALES

Using duality methods, we prove several key properties of the indifference price π for contingent claims. The underlying market model is very general and the mathematical formulation is based on a duality naturally induced by the problem. In particular, the indifference price π turns out to be a convex risk measure on the Orlicz space induced by the utility function.     

WATER BILL ESTIMATION WHEN PRICE IS CRYPTIC: EXPERIENCE FROM WINDHOEK,NAMIBIA

For water policy to be effective, policy makers must know how water users perceive and respond to changes in water prices. However, it is not uncommon for water prices faced by consumers to be unclear. In Windhoek, Namibia, the marginal and average water price is difficult to calculate from the information provided in users' utility bills. This paper applies a hedonic pricing approach to investigate price perceptions of water users in a setting with cryptic price information. Using self‐reported water charges as the dependent variable, the pricing model utilises reported utility characteristics and other factors that may affect perceived price. Low‐income standpipe water users report a weighted average monthly charges of N$24.68, whereas users in high income segments report N$521.34. This reflects differences in service levels, possible subsidies to low‐income users and potential errors in respondents' understanding of their water price. Average price per litre (N$11.78 for the low‐use segment; N$1.89 for the highest segment of Tier 1 water use) tends to be perceived as higher by those with lower water use even though average prices in the relevant range should generally be identical.     

小户型设计中的扩展艺术

由于房价高企,城市人口增多,小户型成为年轻人的热门选择。户型虽小但是生活却不会因此而缩小,如何在有限的空间中创造出最大的使用功能,是目前很受关注的一个问题。因为小户型的空间划分和布局受到户型和面积的限制,装修时往往导致房屋空间功能不全,或者房屋的整体协调性美观程度降低。因此在装修前,需要按照自己的需求对空间进行重新划分,使其在更合理化、人性化,同时整体协调,不杂乱。只要有合理的布局,小户型也可以拥有舒适的生活空间。     

农产品流通中逆向物流与价值链最大化研究

分析了当前我国农产品流通中存在的问题,提出了通过逆向物流实现农产品价值链的最大化,从而放大农产品在从农村到城镇的逆向流通的价值效应.通过优化物流运送方式,探索出了农产品逆向流通效益最大化的运作模式,提出农产品流通各个供应链要强化协作,各自发挥优势,从而实现双向共赢.     

Multivariate risk aversion and uninsurable risks: Theory and applications

The objective of this paper is to develop conditions for global multivariate comparative risk aversion in the presence of uninsurable, or background, risks, and thus generalize Kihlstrom and Mirman [1974] and Karni [1979,1989]. We analyze von Neumann-Morgenstern (VNM) utility functionsas well as smooth preference functionals which are nonlinear in distribution but locally linear in probabilities. In each case we provide an economic application which illustrates how our theorems can be used. We analyze a risk sharing, a portfolio choice, and a labor supply problem for VNM utility functions, and the optimal allocation of effort to risky technologies in the presence of a random supply (or quality) of a public good for nonlinear preference functionals. We consider thecase where the random variables are mean-independent as well as the case where they are independent. In the labor supply application for VNM utility functions, we show that if the two risks are independent, the comparative statics effect of greater risk aversion on labor supply in the presence of a background non-wage income risk is determined by a monotonic relationship between labor supply and the wage rate under certainty. That is, we extend the applicability of the Diamond-Stiglitz [1974]-Kihlstrom-Mirman [1974]single-crossing property to the case where an independent background risk is present.     

不可再生资源的最优储备与开发战略控制模型

宏观经济系统中，不可再生资源储备与开发的战略决策，是该系统中物流动态发展的基础，更是系统经济可持续发展，并在未来经济竞争中维持资源优势的决定性要不比，在进行了五种战略思考的基础上，构建了四个不可再生资源的最优储备与开发的战略控制模型。     

A geometric approach to portfolio optimization in models with transaction costs

We consider a continuous-time stochastic optimization problem with infinite horizon, linear dynamics, and cone constraints which includes as a particular case portfolio selection problems under transaction costs for models of stock and currency markets. Using an appropriate geometric formalism we show that the Bellman function is the unique viscosity solution of a HJB equation.Mathematics Subject Classification (1991): 60G44JEL Classification: G13, G11This research was done at Munich University of Technology supported by a Mercator Guest Professorship of the German Science Foundation (Deutsche Forschungsgemeinschaft). The authors also express their thanks to Mark Davis, Steve Shreve, and Michael Taksar for useful discussions concerning the principle of dynamic programming.