A comparison of Logistic and Harvey models for electricity consumption in New Zealand

There have been a number of forecasting models based on various forms of the logistic growth curve. This paper investigates the effectiveness of two forms of Harvey models and a Logistic model for forecasting electricity consumption in New Zealand. The three growth curve models are applied to the Domestic and Non-Domestic sectors and Total electricity consumption in New Zealand. The developed models are compared using their goodness of fit to historical data and forecasting accuracy over a period of 19 years. The comparison revealed that the Harvey model is a very appropriate candidate for forecasting electricity consumption in New Zealand. The developed models are also compared with some available national forecasts.     

On the (non-)lattice structure of the equilibrium set in games with strategic substitutes

This paper studies models where the optimal response functions under consideration are not increasing in endogenous variables, and weakly increasing in exogenous parameters. Such models include games with strategic substitutes, and include cases where additionally, some variables may be strategic complements. The main result here is that the equilibrium set in such models is a non-empty, complete lattice, if, and only if, there is a unique equilibrium. Indeed, for a given parameter value, a pair of distinct equilibria are never comparable. Therefore, with multiple equilibria, some of the established techniques for exhibiting increasing equilibria or computing equilibria that use the largest or smallest equilibrium, or that use the lattice structure of the equilibrium set do not apply to such models. Moreover, there are no ranked equilibria in such models. Additionally, the analysis here implies a new proof and a slight generalization of some existing results. It is shown that when a parameter increases, no new equilibrium is smaller than any old equilibrium. (In particular, in n-player games of strategic substitutes with real-valued action spaces, symmetric equilibria increase with the parameter.)      

ELECTIONS AND THE THEORY OF CAMPAIGN CONTRIBUTIONS: A SURVEY AND CRITICAL ANALYSIS*

The formal theory of campaign contributions in elections has expanded in the past decade. The basic assumptions and results of these models are examined and analyzed. The assumptions of the models are often inappropriate for the political actors considered and the results are sometimes not empirically supported. We suggest ways in which these models may be altered to alleviate some of these problems.     

The Effects of Delays on the Stability and Rate of Convergence to Equilibrium of Oligopolies*

The stability of oligopolies is investigated using the Cournot strategy and a general output adjustment procedure. Information delays are incorporated in the adjustment procedure and their specific effects upon the dynamic stability of oligopolies is investigated. The stability of equilibrium for discrete models is unaffected by information delays and remoteness of planning horizons; however the rate of convergence to equilibrium may be slowed. For continuous models with delays, some restraints are required for stability.     

Semiparametric Estimation of Simultaneous-Equation Microeconometric Models with Index Restrictions

This article introduces semiparametric methods for the estimation of simultaneous-equation microeconometric models with index restrictions. The methods are motivated by a semiparametric minimum-distance procedure, which unifies the estimation of both regression-type and linear or nonlinear simultaneous-equation models without emphasis on the construction of instrumental variables. Single-equation and systematic estimation methods and optimal weighting procedures are considered. The estimators are √ n -consistent and asymptotically normal. For the estimation of nonparametric regression and some sample selection models where the variances of disturbances are functions of the same indices, the optimal weighted estimator attains Chamberlain's efficient bound for models with conditional moment restrictions. The weighted estimator is shown to be optimal within a class of semiparametric instrumental variables estimators.
JEL classification numbers: C14, C24, C34.     

Measuring persistence in aggregate output: ARMA models, fractionally integrated ARMA models and nonparametric procedures

Econometric issues in the estimation of persistence in macroeconomic time series are considered. In particular, the relative merits of estimates based on ARMA models, ARFIMA models and nonparametric procedures are investigated. It is shown that ARFIMA models are inappropriate for the purpose of estimating persistence. Furthermore, some of the criticism leveled in the literature against the use of ARMA models for estimating long run properties is put into perspective. Methodological issues arising in the estimation of ARMA models that are relevant to estimation of persistence are discussed. It is shown how overparameterization of an ARMA model may lead to severely downward biased estimates of persistence. The theoretical results are employed to explain some of the findings in Campbell & Mankiw (1987a) and Christiano & Eichenbaum (1990). The methodological aspects of the paper are also relevant for the problem of estimating the value of a spectral density at any given frequency. An empirical study confirms persistence estimates reported in Campbell & Mankiw (1987a), and shows that ARMA models as well as nonparametric procedures give very similar estimates of persistence if properly applied. First version received: May 1996/final version received: March 1998     

Binomial innovation diffusion models with dynamic potential adopter population

Models for describing the time pattern of the diffusion processes for innovations are used by researchers in various disciplines. These models are in general binomial models—binomial in the sense that they focus their attention on two causal variables: 1) that part of the population who have already adopted the innovation, and 2) the rest of the population who are potential adopters. However, these models have a serious limitation in that the potential adopter population is assumed to remain constant over time. This paper presents some modified binomial innovation diffusion models that incorporate dynamic potential adopter populations. Moreover, the developed models are applied to some case studies, and their superiority in forecasting the time pattern of diffusion is also included in this presentation.     

Computation of non-linear continuous optimal growth models: experiments with optimal control algorithms and computer programs

In this paper we discuss the use of optimal control methods for computing non-linear continuous optimal growth models. We have discussed various recently developed algorithms for computing optimal control, involving step-function approximations, Runge–Kutta solutions of differential equations, and we suggest that the discretization approach is preferable to methods which solve first-order optimality conditions. We have surveyed some powerful computer programs by : , and for computing such models numerically. These programs have no substantial optimal growth modelling applications yet, although they have numerous engineering and scientific applications. A computer program named by is developed in this study. Results are reported for computing the Kendrick–Taylor optimal growth model using and programs based on the discretization approach. References are made to the computational experiments with and . The results are used to compare and evaluate mathematical and economic properties, and computing criteria. While several computer packages are available for optimal control problems, they are not always suitable for particular classes of control problems, including some economic growth models. The -based and , however, offer good opportunities for computing continuous optimal growth models. It is argued in this paper, that optimal growth modellers may find that these recently developed algorithms and computer programs are relatively preferable for a large variety of optimal growth modelling studies.     

On a family of data-based transformed models useful in forecasting technological substitutions

This paper examines, via real data, some well known models for technology substitution analysis. We propose a family of data-based transformed models that will include the models under examination as special cases. The basic thrust of the paper is the recognition that for technology substitution analysis, the observations are time series data and hence are not independent. Also, the functional form of the model should be determined by both theoretical considerations as well as the data on hand. This suggests that the traditional ordinary least squares procedure used in estimating the parameters and the resulting forecasting procedures are not adequate. The existing models examined here are Fisher–Pry, Gompertz, Weibull, and Normal. We stress the statistical aspects of the models and their relative merits in terms of predictive power. The criteria used for the purpose of comparison are the mean squared deviation and the mean absolute deviation of the predicted values compared with the actual observations.     

The impact of uncertainty in a class of objective functions

This note analyzes some properties of a class of models involving optimization under uncertainty. Such models are characterized by a specific form of the objective function which is frequently encountered by economists. The discussion presented below generalizes a method which has been applied by several theoreticians [1–4, 8] to the analysis of specific topics in the theory of the firm and the problem of investment under uncertainty. This method makes use of a specific parameterization of risk and imposes some restrictions on decision makers' behavior, thus implying a model not as general as the one presented by Rothschild and Stiglitz [6, 7]. However, the present model is still plausible and affords some definite results where more general models are ambiguous.     

Limits and possibilities of large-scale long-range societal models

It is argued that the appropriate criteria for evaluating large-scale long-range societal (or “world”) models differ significantly from the criteria that are appropriate for short-range econometric models or for small “toy” models. World models are designed to elucidate major societal problems arising from the interaction of many loosely connected factors—demographic, economic, technological, and environmental—that can be safely neglected in short-range extrapolative models. World models are also intended to explore the implications of long-range policy alternatives. Consequently, it is important that world models be phenomenological, rather than statistical, and they must “capture” the essence of some inherently nonlinear phenomena. This implies achieving qualitative realism without imposing an unwarranted assumption of causal determinism. Unfortunately, the mathematical characteristics of large nonlinear systems may essentially preclude meaningful long-run forecasts.     

Complexity concepts and the limitations of computable models

As they are implemented in modern computers, computable languages and computable models allow a new approach to logical and scientific thinking. Complexity and decidability problems imply some fundamental limitations to deterministic models. Some striking examples are given by large interactive programs. Different complexity concepts may be distinguished for the representations of data and for algorithms, with consequences relative to the feasibility of models. They are applied to various domains: history, power and politics, economy, and living beings.     

Symmetry-breaking in two-player games via strategic substitutes and diagonal nonconcavity: A synthesis

This paper is an attempt to develop a unified approach to symmetry-breaking in strategic models arising in industrial organization by constructing two general classes of two-player symmetric games that always possess only asymmetric pure-strategy Nash equilibria. These classes of games are characterized in some abstract sense by two general properties: payoff nonconcavities and some form of strategic substitutability. Our framework relies on easily verified assumptions on the primitives of the game, and relies on the theory of supermodular games. The underlying natural assumptions are satisfied in a number of two-stage models with an investment decision preceding product market competition. To illustrate the generality and wide scope for application of our approach, we present some existing models dealing with R&D, capacity expansion and information provision, which motivated this study.     

Sensitivity of consumption to income and to government purchases: some specification and estimation issues

The paper derives a nonlinear error-correction model (ECM) for consumption and shows that existing models that are based on quadratic utility, combine permanent income and current-income consumption, and nest (or could nest) the hypothesis of substitutability between private consumption and government purchases are special cases of the ECM. The importance of some econometric issues that have not received proper attention in the literature is demonstrated by estimating the models using US aggregate quarterly data, 1953:1-1992:4. The evidence suggests that the ECM produces more reliable estimates than do the existing restrictive models.     

行为资产定价理论综述

如何刻画投资者行为是资产定价理论 50年来发展的主要脉络。在消费资本资产定价模型基础上 ,通过修正投资者的效用函数而发展起来的行为资产定价理论 ,对投资者行为的认识达到了新的高度。本文构造了行为资产定价的一般均衡研究框架 ,指出了此框架与行为金融理论的区别 ,并在此框架下 ,综述了当前流行的行为资产定价模型。文章最后分析了行为资产定价理论的下一步发展方向。     

不同文化背景下的心理契约研究——基于中美比较的视角

心理契约在一定程度上受到文化因素的影响,文章就中美两国不同文化背景下,员工心理契约的形成、类型、性质和违背等方面的差异进行了对比分析,旨在探讨适应中国本土文化的心理契约管理模式。     

The Monetary Approach to the Exchange Rate Determination for a “Petrocurrency”: The Case of Norwegian Krone

This paper, by following vector error correction modeling, empirically investigates some of the popular monetary models of the NOK/USD rate. The empirical results suggest that there is some scope for the monetary approach to explain the development of the NOK/USD during the period from 1997 to 2008. The coefficients in the co-integration equation of both money and output differentials are statistically significant and consistent with any of the forms of the monetary models. Moreover, empirical evidence for the proportionality between the exchange rate and relative money is provided. Our findings are robust across different measures of inflation expectations. Although there is no clear evidence regarding the exact version of the monetary model, the estimated unrestricted error correction models can fit the actual NOK/USD exchange rate. Finally, the short-term dynamics of the exchange rate are significantly affected by changes in crude oil prices.     

中国大豆期货市场最优套期保值比率的实证研究

在总结评述国际上成熟的最优套期保值比率估计方法的基础上,采用OLS、VAR、B-ECM、B-GARCH、ECM-B-GARCH五种模型和Lien提出的套期保值绩效衡量指标,对我国大豆期货市场的套期保值比率和套期保值绩效进行了实证研究。结果表明:对于中国大豆期货市场而言,按照OLS模型估计的最优套期保值比率进行动态套期保值能够最大程度地降低风险;基于VAR模型与B-ECM模型的结果次之;按照B-GARCH模型和ECM-B-GARCH模型估计的最优套期保值比率进行动态套期保值,风险降低程度最小。     

Some recent developments in capital market theory: A survey

This paper surveys some recent developments in the theory of capital markets. Particular emphasis is given to two strands of the literature. The first covers some recent and fundamental extensions to the theory of risk aversion and the demand for risky assets. These papers are concerned with the effect of non-hedgeable background risk on risk attitudes. The important implications for finance are for the size of the risk premium (the equity premium puzzle) and for the demand for and pricing of contingent claims. For example, background risk may help to explain the apparent over-pricing of options on equity indices. The second topic is interest rate term structure models. Stochastic term structure models try to capture the possible future shapes of the term structure of interest rates. This is relevant for the pricing of contingent claims, in particular for the pricing of interest rate derivatives such as American-style swaptions. The paper will survey the most important recent models in the literature, each of which satisfies the fundamental no-arbitrage property. It will discuss the implications of the models for the pricing of both European-style and American-style options.     

地区科技进步测定中应注意的几个问题

本文在对西方主要科技进步测定模型分析的基础上，着重对我国广泛运用的索洛模型的特点进行了总结和归纳。在实证分析的基础上，针对我国目前地区科技进步测定中存在的种种偏差，提出了相关的应用研究建议。