EQUILIBRIUM BUSINESS CYCLES: THEORY AND EVIDENCE

ABSTRACT. This paper surveys equilibrium business cycles (EBC) theory, which has dominated the business cycle literature since the mid 1970s. It focuses primarily on the real business cycle (RBC) literature the origin of which is traced to the monetary equilibrium business cycle (MBC) model developed by Lucas (1975). RBC and MBC models are themselves related to a wider class of linear stochastic business cycle models which, following Frisch (1933), view the cycle as the result of the propagation, by the economic system, of a series of random shocks. The MBC approach highlighted the importance of monetary shocks but its failure to adequately explain observed fluctuations provided the impetus to the development of the RBC approach, which emphasises the importance of real shocks. This paper also appraises the empirical support for the RBC approach and finds it less than compelling. Given the failure of Keynesian, and equilibrium linear stochastic business cycle models to fully explain economic fluctuations, the Frischian approach to business cycle modelling is called into question. Developments to existing models, which may help to clarify our understanding of business cycle behaviour, are discussed with a view to setting out a research agenda for the 1990s and beyond.     

Market share and warranty costs for renewable warranty programs

A majority of consumer products is associated with some type of warranty. The nature and extent of the warranty affect the sales, market share, costs and profits of many businesses. A warranty can be defined as an assurance from a seller to a buyer that the product sold is guaranteed to perform satisfactorily up to certain length of time, which is the warranty period. In case of product failure within the warranty period, it is assumed that the seller will conform to a rebate policy. In this paper the rebate policy is selected to be linear pro-rata or lump sum. The paper investigates warranty programs that offer customers the option to renew warranty, after an initial period, for a certain premium. The effect of such programs on market share and warranty costs is explored.     

股票价格与宏观经济变量间的实证研究

本文运用协整检验等计量方法对我国股票价格与宏观经济变量间的关系进行了研究。表明股价指数与工业生产值、消费支出、消费价格指数、货币供应量存在长期均衡关系;消费价格指数和货币供给量的变化会引起股价指数的波动,同时股价指数的波动会引致工业生产值和消费支出的变化;股价指数与部分宏观经济变量存在协整关系,一定程度上可以反映我国经济发展的水平。     

Comparative issues between linear and non-linear risk measures for non-convex portfolio optimization: evidence from the S&P 500

Abstract

This article focuses on inferring critical comparative conclusions as far as the application of both linear and non-linear risk measures in non-convex portfolio optimization problems. We seek to co-assess a set of sophisticated real-world non-convex investment policy limitations, such as cardinality constraints, buy-in thresholds, transaction costs, particular normative rules, etc. within the frame of four popular portfolio selection cases: (a) the mean-variance model, (b) the mean-semi variance model, (c) the mean-MAD (mean-absolute deviation) model and (d) the mean-semi MAD model. In such circumstances, the portfolio selection process reflects to a mixed-integer bi-objective (or in general multiobjective) mathematical programme. We precisely develop all corresponding modelling procedures and then solve the underlying problem by use of a novel generalized algorithm, which was exclusively introduced to cope with the above-mentioned singularities. The validity of the attempt is verified through empirical testing on the S&P 500 universe of securities. The technical conclusions obtained not only confirm certain findings of the particular limited existing theory but also shed light on computational issues and running times. Moreover, the results derived are characterized as encouraging enough, since a sufficient number of efficient or Pareto optimal portfolios produced by the models appear to possess superior out-of-sample returns with respect to the benchmark.     

Prediction of stock price movement based on daily high prices

Prediction of stock close price movements has attracted a lot of research interest. Using machine learning techniques, especially statistical classifiers, for day ahead forecasting of the movement of daily close prices of a broad range of several hundreds of liquid stocks is generally not very successful. We suspect that one of the reasons for failure is the relatively high volatility of prices in the last minutes before the market closes. There have been some attempts to use less volatile daily high prices instead, but the studies concentrated only on a specific non-statistical machine learning approach on a small number of specific securities. We show that incorporating statistical classifiers for day ahead daily high price movement predictions in to some simple portfolio management techniques significantly increases their performance. Tests performed on S&P 500 stocks show that such a strategy is robust, i.e. the difference in reliability for different stocks does not vary significantly, and that such a strategy greatly outperforms the S&P 500 index and several other benchmarks while increasing the risk only by a small amount.     

面板数据下的线性混合模型及其在车险费率厘定中的应用

精算师在进行车险净保费信度厘定时可采用关于面板数据的线性混合模型,本文采用每次交通事故平均损失额和事故发生频率作为车险净保费的计算指标。利用2008~2012年31个省、市、自治区5年的数据,建立面板数据下的线性混合模型,选取人均地区生产总值、每平方公里人口数、民用汽车拥有量作为解释变量,得到每次交通事故平均损失额和事故发生频率的估计模型,进而得到纯保费估计。这一研究可为车险费率市场化提供一定的理论支持和参考。     

A DEA model for resource allocation

This paper concerns inverse DEA. The aim is to estimate input/output levels of a given Decision Making Unit (DMU) when some or all of its input/output levels are changed, under preserving the efficiency index. We show that in the case of estimating increased required input vector when the output vector is increased, the current method which uses weakly efficient solution of the relevant multiple objective optimization problem may fail. We propose some sufficient conditions for input estimation.     

Identifying development blocks—a new methodology

The paper specifies a quantitative methodology for exploring development blocks. The concept of ‘development block’ was a major contribution to the historical analysis of industrial transformation by the late Erik Dahmén, but development blocks have mainly been analyzed by qualitative methods and indirect indicators and not statistically identified. In this paper, development blocks are identified by means of a combination of co-integration analysis and Granger causality. Using these techniques, we are able to identify two partially overlapping development blocks in the Swedish economy, formed around the electricity generating sector: one with metal, metal goods, machinery and railways; and another with pulp and paper, chemicals, and machinery.

台商直接投资对我国区域工业增长的影响——以福建省为例的实证分析

笔者根据1989年～2007年福建省统计数据,运用协整检验、Breusch-Godfrey检验和Granger因果检验,对台商直接投资对我国区域工业增长的影响进行实证分析。研究结果表明,两者之间具有较强的相关关系,但不存在长期稳定的协整关系。同时,Granger因果检验表明,台商直接投资与我国区域工业增长之间存在单向因果关系,即台商直接投资是我国区域工业增长的原因,而区域工业增长却不是台商投资增加的原因。最后,本文就进一步扩大利用台资、提高利用台资质量提出了政策建议。     

异方差和多重共线性的影响——模拟蒙特卡洛

通过蒙特卡洛实验,在计量经济学软件R中实现数据生成过程,当古典线性回归模型基本假定中的同方差假定和无多重共线性假定被违背时,参数的显著性检验是否依然有效。