Beyond Time Discounting

The intertemporal tradeoffs made by most persons appear inconsistent when viewed through the lens of the standard time-discounting model. At different times and in different decision contexts, the same individual will often display behavior suggestive of a wide range of discount rates, from strongly positive (indicative of a lack of concern of future consequences) to strongly negative (implying greater concern for the future than the present). We argue that many of these apparent inconsistencies can be attributed to three aspects of time preference that are not part of the conventional model: decreasing impatience, a preference for sequences of outcomes that improve over time, and preference interactions between consumption and payments.     

Generalizations of the KPSS-test for stationarity

We propose automatic generalizations of the KPSS-test for the null hypothesis of stationarity of a univariate time series. We can use these tests for the null hypotheses of trend stationarity, level stationarity and zero mean stationarity. We introduce the asymptotic null distributions and we determine consistency against relevant nonstationary alternatives. We compare the properties of the tests with those of other proposed tests for stationarity. Monte Carlo simulations support the relevance of the tests when an autoregressive process with large positive autocorrelations is likely under the null hypothesis.     

The Impact of Choice Inconsistencies in Stated Choice Studies

A new test procedure revealing mutuallyinconsistent choices has been developed andapplied to Stated Choice data. Our analysisshows that inconsistent choices commonly occurin several Stated Choice tasks. An applicationof the test to the Norwegian Value of Timestudy data shows that failing to excludeinconsistent choices resulted in asubstantially higher Value of time. Theinconsistent choices were made by less educatedparticipants. As the tasks were undertaken inthe easy context of choosing travelalternatives with three attributes,practitioners of more complex and cognitivedemanding designs should be particularilyconcerned with these results.     

Revealing Preferences for Leisure Time from Stated Preference Data

When consumer choice is constrained by time as well as money, willingness to pay can be defined with respect to either numeraire. The two measures can be related formally within a utility-consistent model of choice subject to two constraints. Furthermore, when information is collected on both, the respondent's marginal value of time can be identified. A system of willingness to pay time and money and the marginal value of leisure time is estimated jointly in an application to California whalewatching and whale stock enhancement. The empirical approach can be applied with only minor additions to survey techniques for nonmarket valuation.     

商品房按揭贷款与资金的时间价值

本论述了商品房按揭贷款中，置业应正确认识贷款本金的偿还是按复利计算时间价值的，正确对待贷款购房中的“杠杆作用”。为置业在住房贷款中，代款数额、贷款方式、还款时间、还款方式的确定提出合理建议。     

An Improved Inventory Coordination Model in a Multi-stage Multi-customer Supply Chain

To solve the inventory coordination model in a multi-stage, multi-customer supply chain, this paper first analyzes the third model （integer powers of two multipliers at each firm） studied by Moutaz Khouja （2003）, and the authors take a numerical example to prove that the third model is irrational to miss feasible solution. Then this paper puts up a new improved model （integer multiplier at each firm）, and takes the example to prove it gives better results than the integer powers of two multipliers at each firm.     

如何使用Excel构建动态图表

本文通过实例演示的方式,逐步解析了如何使用Excel来创建动态图表,用简便的窗体控件增强了数据的表现力,使图表的使用者能够直观地动态观察和演示数据的变化趋势,具有很好的理论价值和实际意义。     

PORTFOLIO INSURANCE AND VOLATILITY REGIME SWITCHING

A new equilibrium model of portfolio insurance is presented in order to study the volatility effects of dynamic insurance strategies. While prior research has focused on the relationship between portfolio insurance and the overall level of market volatility, this article shows that the salient feature of portfolio insurance is volatility regime switching. Regime switching is shown to be a necessary condition for portfolio insurance, which provides a new explanation for the pervasive volatility clustering effect that is found in most equity markets. The equilibrium involves a free boundary and the local time of the equilibrium price process at the free boundary plays an important role in solving the model.     

A Note on EOQ Model for Items with Mixtures of Exponential Distribution Deterioration,Shortages and Time-varying Demand

An inventory model is considered in which inventory is depleted not only by demand, but also by deterioration. In this paper, we derive the EOQ model for inventory of items that deteriorates at a mixtures of exponential distributed rate, assuming the demand rate with a continuous function of time. Moreover, the proposed model cannot be solved directly in a closed form, thus we used the computer software IMSL MATH/LIBRARY (1989) to find the optimal reorder time Further, we also find that the optimal procedure is independent of the form of the demand rate. Finally, we also assume that the holding cost is a continuous, nonnegative and non-decreasing function of time in order to generalize EOQ model. Moreover, four numerical examples and sensitivity analyses are provided to assess the solution procedure.     

对名义利率和实际利率的再认识

名义利率和实际利率对投资决策、筹资决策和股利分配政策有重要参考价值。该文对名义利率和实际利率进行了重新定义,同时指出影响名义利率和实际利率的因素并非仅是通货膨胀,还包括信用条件、计息方法、投资期限等多种因素,而且进一步阐述,实际利率并非简单地等于名义利率与通货膨胀之差,名义利率并非总大于实际利率。