APPLYING A GENETIC ALGORITHM TO INTERNATIONAL DIVERSIFICATION OF EQUITY PORTFOLIOS: A SOUTH AFRICAN INVESTOR PERSPECTIVE

This paper uses the genetic algorithm (GA) approach to generate a portfolio optimisation scenario of a South African investor who seeks to maximise return from investing in S&P500, FTSE100, NASDAQ, DOWJONES, CAC40 and the DAX from January 1, 2005, to January 31, 2008, but facing exchange rate risk. The GA searches for the optimal solution in the entire set of financial constraints without looking for partial derivatives of the utility function. Whereas most financial problems require a non‐linear and time‐varying model, the GA, with its survival principle of offspring chromosomes, is better suited to this type of problem than local optimisation methods. The performance of the GA is compared with two non‐linear models, namely the quadratic mean‐variance (QMV), which maximises the portfolio mean‐variance, and the quadratic variance minimisation (QVM), which minimises the portfolio variance. The results show that neither the QMV nor the QVM takes into account the domestic investors' risk attitude towards investing in foreign equities and therefore does not provide any international diversification benefits. In addition, the bootstrapping scenario of 10,000 simulations reveals that neither the QMV nor the QVM outperforms the GA in terms of Sharpe ratio and flexibility in dealing with investors' risk attitude towards investing in foreign equities denominated in foreign currencies.     

What do Russians think about transition?1

We use data from the 2006 round of the Russian Longitudinal Monitoring Survey to describe perceptions of the Russian population about the transition process and the role of the state compared with that of free markets. We find that about one‐half of the Russian population is disappointed with transition and a large majority is in favour of high state regulation and state provision of goods and services. High demand for government regulation and increased state intervention coexists with a low level of trust in government institutions and recognition of high and rising levels of corruption. The findings are consistent with the theory developed by Aghion et al. (2009) . In an environment with poor social capital, private business imposes negative externalities on the society and society chooses to demand more state regulation and tolerate corruption to reduce these externalities. We also find that individual perceptions of social capital and corruption co‐vary with the demand for regulation, as predicted by the theory.     

How effective are heuristic solutions for electricity planning in developing countries

Heuristic algorithms have been widely used to provide computationally feasible means of exploring the cost effective balance between grid versus off grid sources for universal electrification in developing countries. By definition in such algorithms however, global optimality is not guaranteed. We present a computationally intensive but globally optimal mixed integer non-linear programming (MINLP) model for electricity planning and use it in a Monte Carlo simulation procedure to test the relative performance of a widely used heuristic algorithm due to [28]. We show that the overall difference in cost is typically small suggesting that the heuristic algorithm is generally cost effective in many situations. However we find that the relative performance of the heuristic algorithm deteriorates with increasing degree of spatial dispersion of unelectrified settlements, as well as increasing spatial remoteness of the settlements from the grid network, suggesting that the effectiveness of the heuristic algorithm is context specific. Further, we find that allocation of off grid sources in the heuristic algorithm solution is often significantly greater than in the MINLP model suggesting that heuristic methods can overstate the role of off-grid solutions in certain situations.     

Selfishness, cooperation, the evolutionary point of view and its implications for economics

The assumed selfishness of market actors could be considered in the context of two perspectives: macroeconomic and microeconomic. The first concerns the market mechanism as the most effective from the social well-being or the wealth of a nation points of view. The latter is based on the premises of the nature of human beings. I have distinguished between two possible ways of understanding selfish forms of behaviour in the market: as rational economic behaviour i.e. the most effective from the gains and losses point of view (i.e. public interests in the works of A. Smith) or as selfish from the psychological point of view (this is mostly presented by J. S. Mill's theory). The first approach seems to be concerned with the creation of the most effective market mechanism from the State's point of view. In the context of historical processes over 400 years, cultural evolution “has been promoting” selfish behaviour; for example, it was widely presented in T. Hobbes' works and then for over 200 years, the theory of A. Smith has been supporting and moulding the institutional context of market and social behaviour. Thus, positive economics describes the market created by the ideas of a neo-classical paradigm, which is based on the normative premises of A. Smith and J. S. Mill. Moreover, the virtual market behaviour described by “effects” (f. e. Veblen's effect) and failures seems to be a manifestation of a discrepancy between market reality and the classical assumptions.The social evolution of human beings has been advantageous to the human species. Moreover, from the social point of view, pro-social behaviour is “natural” as well as desirable and it has been preferred by the cultural evolution. Competitiveness assumes that somebody has to lose, because someone gains. Cooperation looks for gains for all the players. The choice is political, and not imposed by selfishness.     

留置尿管引发泌尿道感染的原因分析与预防措施

总结并分析127例留置尿管的老年患者中28例患者引发泌尿道感染的原因。认为积极的预防、及时的治疗、严格的无菌操作和加强日常护理、治疗原发病是预防感染的有效措施。     

Key problems facing industrial distributors

This article reports on a survey of the problems faced by industrial distributors. Five major problem categories are identified and managerial implications are derived from the findings.     

A look at the public policy conflict regarding the discovery of accountants' tax accrual workpapers

This article focuses on the conflict in public policy between the need to provide the investing public with accurate information with regard to corporate financial statements and the need to provide the IRS with the necessary tools in order to assure corporate compliance with the tax laws of the country. The conflict arises because of the contention of the IRS that it is entitled to have access to an independent auditor's tax accrual workpapers on the one hand, and the contention by CPAs that such access will prevent adequate disclosure to the independent auditor. The article examines the policy questions on both sides of the issue and concludes that regardless of any decision by the Supreme Court in a pendingcase, Congress should pass legislation to resolve the conflict and clearly identify the scope of any previlage accorded with regard to tax accrual workpapers.     

Mark-Choose-Cut Algorithms For Fair And Strongly Fair Division

This paper proposes a new criterion to evaluate algorithms for cake division, by the number of resulting pieces. Then, inspired by the idea of "cut-and-choose", we present "mark-choose-cut" algorithms for fair and strongly fair cake division problems. They are game-theoretic algorithms. The number of resulting pieces is bounded by 2 × 3n-2 + 1 and 4 × 3n-2 + 1, for fair and strongly fair division respectively.     

Differentiation of the Peasantry Under Feudalism and the Transition to Capitalism: In Defence of Rodney Hilton

The focus of the essay is one specific theme pursued by Rodney Hilton: that of differentiation of the English feudal peasantry and the implications this had for the development of capitalism in England. His contribution on this, along with those of E. A. Kosminsky and of Maurice Dobb, are considered and are contrasted with the view of Robert Brenner. For Brenner peasant differentiation has no causal importance: it is an outcome of transformation and not a driving force in its securing. For Hilton, it is central to transformation: it is not an outcome but a determining variable, a causa causans rather than a causa causata. The Brenner position, it is argued, is incomplete in its ignoring of peasant differentiation in feudal England. It was one of Hilton's accomplishments to explore this in scholarly detail, and with analytical precision. It is suggested that if this is abstracted from an adequate examination of the transition to capitalism in England cannot proceed.     

一种实用的域内标记算法及其公平性

本文从6个方面对WTO有关协定的英文文本的语言特点作了分析,结 合翻译实践经验,对其翻译提出些建设性的意见。