Accounting Year Effects Modeling in the Stochastic Chain Ladder Reserving Method

Abstract

In almost all stochastic claims reserving models one assumes that accident years are independent. In practice this assumption is violated most of the time. Typical examples are claims inflation and accounting year effects that influence all accident years simultaneously. We study a Bayesian chain ladder model that allows for accounting (calendar) year effects modeling. A case study of a general liability dataset shows that such accounting year effects contribute substantially to the prediction uncertainty and therefore need a careful treatment within a risk management and solvency framework.     

Business ethics in Italy: The state of the art

Up until now, the work which has been done in Italy might be considered of a preparatory nature. In 1985 and in 1986, the association of Catholic businessmen produced two documents on the ethical implications of economic activity. But in those years, the world of big business, had not yet realised how central the argument was becoming.The first significant signs of interest for business ethics appeared in 1987. In June, 1988, the first Italian National Conference on Business Ethics took place in Milan. The main outcome of that conference has been the constitution of the Italian Chapter of the European Network. In 1988, I founded the first issue of the journal entitled Etica degli-Affari. Promotional efforts have developped along two lines. The first regards programs of executive training and, eventually, consulting. In the second place, efforts are being made to elaborate and introduce codes of ethics in Italian corporations. There are, however, some very fundamental difficulties involved in the promotion of Business Ethics in Italy. The first problem is the fact that Italy is a country with a low ethical temperature. We don't have a strong sense of national identity, nor do we have a strong sense of the state. The second difficulty has to do with the business environment — the Italian business community itself. As a self-conscious, self-aware nucleus of a sector of society, the Italian business community is a very recent, and rather minoritarian social phenomenon.I personally feel that a certain protagonism on the part of prominent business leaders who are quite sensitive to the theme of ethics would prove to be very influential and greatly accelerate the process.Mario Unnia is managing director of Prospecta, a research firm, Milan, Italy. He has lectured and published extensively in the fields of Business and Public Policy, Corporate Culture and Labour Relations. He has founded and is chairman of the Italian Business Ethics Network. He is editor of Etica degli Affari.     

Extreme Value Theory and Archimedean Copulas

Using the language of copulas, we generalize the famous Fisher-Tippett Theorem of extreme value theory to the case with sequences of dependent random variables. The dependence structure is modelled using archimedean copulas. This generalization enables to study the behaviour of the maxima of dependent random sequences.     

Conditional Value-at-Risk,spectral risk measures and (non-)diversification in portfolio selection problems – A comparison with mean–variance analysis

We study portfolio selection under Conditional Value-at-Risk and, as its natural extension, spectral risk measures, and compare it with traditional mean–variance analysis. Unlike the previous literature that considers an investor’s mean-spectral risk preferences for the choice of optimal portfolios only implicitly, we explicitly model these preferences in the form of a so-called spectral utility function. Within this more general framework, spectral risk measures tend towards corner solutions. If a risk free asset exists, diversification is never optimal. Similarly, without a risk free asset, only limited diversification is obtained. The reason is that spectral risk measures are based on a regulatory concept of diversification that differs fundamentally from the reward-risk tradeoff underlying the mean–variance framework.     

RANDOM WALK TESTS FOR LATIN AMERICAN EQUITY INDEXES AND INDIVIDUAL FIRMS

In this study we re-examine the presence of random walk in stock prices in Brazil and Mexico. We employ variance ratio tests on weekly stock returns for indexes as well as individual firms. The results reveal mean aversion in Mexico at both the index level and the firm level. In contrast, the Brazil indexes show a greater tendency toward random walk; however, the results for the individual firms suggest mean reversion. The results cannot be attributed to a firm size effect. Evidence is presented in favor of a greater degree of nonsynchronous trading for Brazilian securities than for Mexican securities.     

Budgeting in Times of Economic Crisis

This article examines how corporate reliance on budgets is affected by major changes in the economic environment. We combine survey and archival data from the economic crisis that began in 2008. The results indicate that budgeting became more important for planning and resource allocation but less important for performance evaluation in companies affected more strongly by the 2008 economic crisis. Additional evidence from interviews and data gathered in a focus group further illustrate these results and show the changes organizations have introduced to respond to the economic crisis. Taken together, and contrary to more general conclusions from the literature such as an overall increase or decrease in the importance of budgeting, we find that companies emphasize certain budgeting functions over others during economic crises.     

Deep and Proximate Determinants of the World Income Distribution

This paper studies the deep and proximate determinants of the evolution of the cross-country distribution of GDP per worker in the period 1960–2008 by a novel method based on an information criterion. We find that countries of our sample follow three distinctive growth regimes identified by two deep determinants, namely life expectancy at birth in 1960 and the share of Catholics in 1965, and that each regime is characterized by non-linearities. Growth regimes appear to be the main cause of the increased inequality and polarization, while technological catch-up, proxied by the initial level of GDP per worker, acts in the opposite direction. Finally, human capital marginally reduces polarization, while investment rates and employment growth have no distributional effect.     

Current Accounts in the Long Run and the Intertemporal Approach: A Panel Data Investigation

This paper is a theory‐based study of the long‐run determinants of the current account (CA). For many OECD economies after the Second World War, there has been more long‐run variation in the CA data than is emphasised by a ‘Permanent Income’ version of the intertemporal approach that is based on consumption‐smoothing and that allows only transitory CA imbalances. A theoretical model of the CA is developed, based on the ‘broader’ variant of the intertemporal approach that stresses the long‐term component of the CA. We find that some key theoretical predictions hold, while others fail, validating the approach but also pointing to its limitations.     

No News Is Good News: Stochastic Parameters versus Media Coverage Indices in Demand Models after Food Scares

We develop a stochastic parameter approach to model the time-varying impacts of food scares on consumption, as an alternative to the inclusion of news coverage indices in the demand function. We empirically test the methodology on data from four food scares, the 1982 heptachlor milk contamination in Oahu, Hawaii and the bovine spongiform encephalopathy and two Escherichia coli scares on U.S. meat demand over the period 1993–9. Results show that the inclusion of time-varying parameters in demand models enables the capturing of the impact of food safety information and provides better short-term forecasts.