Simulating the Evolution of the Implied Distribution

Motivated by the implied stochastic volatility literature (Britten–Jones and Neuberger, forthcoming; Derman and Kani, 1997; Ledoit and Santa–Clara, 1998) this paper proposes a new and general method for constructing smile–consistent stochastic volatility models. The method is developed by recognising that option pricing and hedging can be accomplished via the simulation of the implied risk neutral distribution. We devise an algorithm for the simulation of the implied distribution, when the first two moments change over time. The algorithm can be implemented easily, and it is based on an economic interpretation of the concept of mixture of distributions. It can also be generalised to cases where more complicated forms for the mixture are assumed.     

An appropriate model for joint regional action in southern Africa after apartheid

Market‐based integration is not appropriate to the joint development of the southern African region; the region's political, technical and institutional immaturity requires instead loose, function‐based economic cooperation. This will also facilitate intraregional trade. Subregions in the meantime could progress to higher levels of integration: international experience has shown that successful integration is most likely when it takes place on the basis of ‘regions within regions’. Cooperative development of the subcontinent is likely to be best achieved through the ‘concentric circles’ approach to regional cooperation, in which a revised Southern African Customs Union‐Common Monetary Area forms the highly integrated core of a loose, function‐based cooperative arrangement covering the whole of southern Africa.     

Making Financial Goals and Reporting Policies Serve

The main. nancial goal of Progressive Insurance, the third largest underwriter of auto insurance in the U.S., has remained the same since the late 1960s. Expressed in three words, "96 and grow," the goal tells the company's managers to pursue all growth opportunities while maintaining a "combined ratio" no higher than 96, or what amounts to a minimum 4% spread between revenues (premiums) and costs (including expected losses). Thanks in part to the clarity of mission provided by this goal, the company has produced an average 15% rate of growth in revenues and earnings, along with a remarkably stable 15% return for its shareholders, since going public in 1971.
Progressive's simplicity and clarity of mission is also partly responsible for another of the company's distinctive policies: product pricing that, while disciplined, is aggressive and highly decentralized. Having invested some $500 million per year developing statistical models for pricing individual customer risks and acquisition costs, the company was among the. rst in its industry to underwrite "non-standard" risks. And aided by sophisticated pricing models, each of Progressive's 100 or so local product managers are charged with adapting those models to come up with premiums for their own regions.
To go along with its strategic and organizational innovations, Progressive also has an innovative disclosure policy. Apart from SEC reports, the company's communications seldom mention earnings or earnings per share, and the company has never provided earnings guidance. With the passage of Reg. FD in late 2000, the company brie. y considered offering guidance. But in the spring of 2001, the board decided instead to provide monthly releases of its realized combined ratio. Since adoption of this new disclosure policy, Progressive has seen a 50% drop in the volatility of its stock price.     

STUDIES OF MANAGERIAL JOBS AND BEHAVIOUR: THE WAYS FORWARD

The main achievements and limitations of studies of managerial jobs and behaviour are summarized drawing upon the review articles of Martinko and Gardner (1985) and Hales (1986). Ways forward are explored by developing a map of the field for future studies, which is shown in figure 1. The figure has three aims: to show different areas for research; to help in identifying neglected areas that could be fruitful ways forward; and to show the interrelationship between different aspects of the study and thus to act as a guide for data collection. The main purpose of the article is to be a guide to what can, and what might most fruitfully, be studied, but some suggestions are also made about methods.     

The Self-concept of Black and White Women: The Influences Upon Its Formation of Welfare Dependency, Work Effort, Family Networks, and Illnesses

Abstract . The concept of “self-efficacy” is used to test the hypothesis that the negative self-concept of welfare recipients coniributes to long term psychological and material dependency on such assistance. Self-efficacy focuses on the extent to which people are able to produce and regulate events in their lives and is associated with self-imposed performance expectations. The extent to which the minority status which Blacks occupy in this society decreases self efficacy relative to Whites is examined, using information generated from structured interviews with 290 low income Black and White women. Operationalizing the concept of self-efficacy with appropriate controls for socioeconomic status, family composition and other factors results in finding no racial differences in sense of self-efficacy between Black and White women. Observed differences in patterns of receipt of public assistance are found to be more directly related to the persistence of structural barriers to upward mobility that have differential impacts on Blacks and Whites. Long term receipt of public assistance is found to adversely affect both self-worth and work orientation/perceived efficacy for all women.     

All politics is local: The effect of fiscal and monetary constitutions on economic policy

The rules of behavior for the monetary authorities changed in 1933 and 1947 and the Fed temporarily changed its operating procedures in 1979, but these changes did not alter the fact that the monetary authorities serve as the agent of the fiscal authorities. On the fiscal side, a shift from a centralized process to one where Congress was composed of a set of individual entrepreneurs altered the fiscal focus from the national economy to one of localized interests. This change led to a more autoregressive and deficit-prone federal budget and changed the interaction between monetary and fiscal policy. It also elevated the status of monetary policy to the extent where financial markets react to every utterance from the monetary authorities.     

Sociology,risk and the environment: a material-semiotic approach

Abstract

Sociology has made significant contributions to the conceptualisation of risk and critique of technical risk analysis. It has, however, unintentionally reinforced the division of labour between the natural/technical and social sciences in risk analysis. This paper argues that the problem with conceptualisations of risk is not a misplaced emphasis on calculation. Rather, it is that we have not adequately dealt with ontological distinctions implicit in both sociological and technical work on risk between material or objective risks and our socially mediated understandings and interpretations of those risks. While acknowledging that risks are simultaneously social and technical, sociologists have not, in practice, provided the conceptual and methodological tools to apprehend risk in a less dualistic manner. This limits our ability both to analyse actors and processes outside the social domain and to explore the recursive relationships between risk calculus, social action and the material outcomes of risk. In response, this paper develops a material-semiotic conceptualisation of risk and provides an assessment of its relevance to more sociologically informed risk governance. It introduces the ideas of co-constitution, emergent entities and enactment as instruments for reconciling the material and social worlds in a sociological study of risk. It further illustrates the application of a material-semiotic approach using these concepts in the nuclear industry. In deconstructing social–material dualisms in the sociology of risk, this paper argues that a material-semiotic conceptualisation of risk enables both technical and social perspectives on risk not only to coexist but to collaborate, widening the scope for interdisciplinary research.     

Predicting Corporate Bankruptcy: An Evaluation of Alternative Statistical Frameworks

Corporate bankruptcy prediction has attracted significant research attention from business academics, regulators and financial economists over the past five decades. However, much of this literature has relied on quite simplistic classifiers such as logistic regression and linear discriminant analysis (LDA). Based on a large sample of US corporate bankruptcies, we examine the predictive performance of 16 classifiers, ranging from the most restrictive classifiers (such as logit, probit and linear discriminant analysis) to more advanced techniques such as neural networks, support vector machines (SVMs) and “new age” statistical learning models including generalised boosting, AdaBoost and random forests. Consistent with the findings of Jones et al. ( 2015 ), we show that quite simple classifiers such as logit and LDA perform reasonably well in bankruptcy prediction. However, we recommend the use of “new age” classifiers in corporate bankruptcy modelling because: (1) they predict significantly better than all other classifiers on both the cross‐sectional and longitudinal test samples; (2) the models may have considerable practical appeal because they are relatively easy to estimate and implement (for instance, they require minimal researcher intervention for data preparation, variable selection and model architecture specification); and (3) while the underlying model structures can be very complex, we demonstrate that “new age” classifiers have a reasonably good level of interpretability through such metrics as relative variable importances (RVIs).