Hierarchical structures in the aggregation of premium risk for insurance underwriting

In the valuation of the Solvency II capital requirement, the correct appraisal of risk dependencies acquires particular relevance. These dependencies refer to the recognition of risk diversification in the aggregation process and there are different levels of aggregation and hence different types of diversification. For instance, for a non-life company at the first level the risk components of each single line of business (e.g. premium, reserve, and CAT risks) need to be combined in the overall portfolio, the second level regards the aggregation of different kind of risks as, for example, market and underwriting risk, and finally various solo legal entities could be joined together in a group.

Solvency II allows companies to capture these diversification effects in capital requirement assessment, but the identification of a proper methodology can represent a delicate issue. Indeed, while internal models by simulation approaches permit usually to obtain the portfolio multivariate distribution only in the independence case, generally the use of copula functions can consent to have the multivariate distribution under dependence assumptions too.

However, the choice of the copula and the parameter estimation could be very problematic when only few data are available. So it could be useful to find a closed formula based on Internal Models independence results with the aim to obtain the capital requirement under dependence assumption.

A simple technique, to measure the diversification effect in capital requirement assessment, is the formula, proposed by Solvency II quantitative impact studies, focused on the aggregation of capital charges, the latter equal to percentile minus average of total claims amount distribution of single line of business (LoB), using a linear correlation matrix.

On the other hand, this formula produces the correct result only for a restricted class of distributions, while it may underestimate the diversification effect.

In this paper we present an alternative method, based on the idea to adjust that formula with proper calibration factors (proposed by Sandström (2007)) and appropriately extended with the aim to consider very skewed distribution too.

In the last part considering different non-life multi-line insurers, we compare the capital requirements obtained, for only premium risk, applying the aggregation formula to the results derived by elliptical copulas and hierarchical Archimedean copulas.     

Is the use of bank debt as a governance mechanism conditioned by the financial system? The cases of Chile and Spain

We test whether the use of bank debt as a governance mechanism is conditioned by the financial system in which firms operate. Our results indicate that the legal and institutional environment determines the use of bank debt to finance growth opportunities. Firms use bank debt to finance their growth opportunities when the country's banking system contributes to solving agency and asymmetric information problems and avoiding information monopoly costs. The evolutionary process of the financial systems in each country means that market imperfections such as information asymmetry or agency costs can have a diverse influence on firms’ bank debt decisions.     

From necessities to imaginary worlds: Structural change,product quality and economic development

In this paper we explore how innovation and structural change affected economic development in the long run, by which we mean a period such as the one between the industrial revolution and the present. We separate the period since the industrial revolution into two sub periods, which we call ‘necessities’ and ‘imaginary worlds’ and focus on three trajectories, increasing productive efficiency, increasing output variety, and increasing output quality and differentiation. In the paper we show how a combination of the three trajectories gave rise to the transition between ‘necessities’ and ‘imaginary worlds’ and propose a mechanism of economic development which could have given rise to the type of economic system which we can observe today. To create growing output quality and differentiation higher competencies were required. These higher competencies required higher levels of education and demanded higher wages, which contributed to raise consumers' purchasing power. These phenomena, combined with the income effect of the creation of new sectors, generated the disposable income with which consumers could purchase the new, higher quality, non necessities, goods and services generated by innovation. In the paper we study the impact of several model parameters on the stability of the virtuous circle previously described.     

Innovation in knowledge-based professional service firms. An integrated conceptual model*

ABSTRACT

The current paper offers a new conceptual model to understanding innovation processes in professional service firms, to make hidden relationships more explicit and to find out what are the issues still unexplored. The paper employs a systematic literature review, and draws upon original categorizations of extant literature, to identify main processes for each category of PSFs. It unveils connections among a wide range of factors setting a conceptual model for innovation pathways and highlighting neglected questions relevant from both the theoretical and the practical perspectives.     

Explaining the World Heritage List: an empirical study

The UNESCO World Heritage List is designed to protect the global heritage. We show that, with respect to countries and continents, the existing World Heritage List is highly imbalanced. Major econometric determinants of this imbalance are historical GDP, historical population, area in square kilometers of a country, and number of years of high civilization. Surprisingly, economic and political factors, such as membership on the UN Security Council, which should be unrelated to the value of a country’s heritage and therefore should have no impact, are shown to have a systematic impact on the composition of the World Heritage List.     

Product variety, competition and economic growth

In this paper, we study the relationship between competition and economic growth using a model of economic development through the creation of new sectors. In our model, competition has both an intra- and an inter-sector component. We find that the best conditions for economic development are achieved when a suitable ratio of inter- to intra-sector competition is achieved. This ratio constitutes a compromise between providing a temporary monopoly to the first entrepreneur (low inter-sector competition) and creating enough imitation to expand the sector (intra-sector competition).     

On the nonexistence of recursive equilibrium in stochastic OLG economies

We study a class of stochastic Overlapping generations (OLG) economies that have one-memory equilibria, that is equilibria that are determined by the current and past realizations of the states of uncertainty. This class is negligible, but important. In particular, it contains all the known examples of nonexistence of recursive equilibrium. We show that, within this restricted domain, the existence of recursive equilibrium is actually typical, and such examples are therefore nonrobust. We thank Felix Kubler, Herakles Polemarchakis and Steve Spear for many useful discussions. This paper was started while the first author was visiting Columbia Business School.     

Trade and revelation of information

We consider an economy with asymmetric information and two types of agents, fully informed and uninformed. Uninformed agents update their information observing equilibrium prices and the equilibrium levels of other agents’ excess demand. We show that, for a generic set of economies, there are rational expectations equilibria which are partially revealing on an open, dense set of signals of positive Lebesgue measure, provided that the dimension of the signal space is sufficiently larger than the dimension of the commodity space.     

Political pressures and the credibility of regulation: can profit sharing mitigate regulatory risk?

When price-cap rules determine the structure of prices for a long period, they suffer a credibility problem and introduce an element of risk especially if a firm’s profits are “too large”. Profit sharing may be seen as a device to pre-determine price adjustments and thus to decrease regulatory risk. We analyse the effects of profit sharing on the incentives to invest, using a real option approach. Absent credibility issues, a well designed profit sharing system may be neutral relative to a pure price cap. With regulatory risk, profit sharing is preferable to a pure price-cap one, if it intervenes for high enough profit levels.

De-hubbing of airports and their recovery patterns

The paper analyzes cases of de-hubbing in air transport between 1997 and 2009. It initially addresses the conditions to be met for airports to be identified as de-hubbing cases. Second, it examines what happens after de-hubbing by clustering the cases into homogenous groups that show that, on average, airports that experienced de-hubbing did not recover their original traffic within five years and that de-hubbing is likely to be irreversible. When hub carriers were replaced at least partially by low-cost carriers, airports on average recovered faster. De-hubbing adversely affects the number of destinations served less severely than the seats offered by carriers.