bluuebunny/crossref_metadata_2025 huggingface dataset:
Acceptability of internet interventions for youth mental health in Vietnam
Authors: Sobowale K. , Nguyen M. , Weiss B. , Van T. T. Hai , Trung L. T.
Published: July 2016

Background.

Despite high levels of mental illness, Vietnamese youth have limited access to mental health care. Internet interventions, evidence-based psychotherapy treatments delivered through the internet, have the potential to increase access to mental health for youth in Vietnam. This study explored the perceptions of youths and parents toward internet interventions for youth mental health.

Methods.

Four focus groups were conducted with youths (n = 20) and parents (n = 20) in Danang, Vietnam. The Technology Acceptance Model was used a framework for focus group questions. The data were analyzed using direct content analysis.

Results.

Most youths and parents agreed that the internet serves well as a care delivery model. Participants expressed that the web would be useful for psychoeducation and sharing and receiving information with others. Both groups reported lack of awareness of web-based interventions and logistical concerns regarding access as main barriers. In addition, many parents were concerned about internet addiction. Specific adaptations in Vietnam such as standalone internet service centers and partnering with local organizations may benefit uptake of internet interventions.

Conclusion.

This study suggests that internet-based programs for youth mental health, particularly interventions incorporating psychoeducation and social networking components, will be well received in Vietnam. Barriers need to be addressed to successfully implement internet-based treatment. Future initiatives should incorporate acceptance models to improve development of internet interventions for youth.
Coworkers’ Relationship Quality and Interpersonal Emotions in Team-Member Dyads in China: the Moderating Role of Cooperative Team Goals
Authors: Lam Catherine K. , Huang Xu , Walter Frank , Chan Simon C. H.
Published: July 2016

This study investigates the origins of discrete interpersonal emotions in team-member dyads using two independent samples from an education institute and a telecommunication services company in China. Results across both studies showed that the quality of team members’ dyadic relationships positively relates to interpersonal admiration, sympathy, and envy, and negatively relates to interpersonal contempt. Furthermore, teams’ cooperative goals moderate these dyad-level linkages. The association of relationship quality with interpersonal emotions is particularly pronounced in teams with less cooperative goals but buffered in teams with more cooperative goals. Finally, on the individual level of analysis, envy and contempt are inversely associated with team members’ work performance, objectively measured. These findings provide new insights about key antecedents and crucial moderators in the development of interpersonal emotions in Chinese work teams and reiterate the relevance of these emotions for tangible performance outcomes.
Transformations of the Sacred in East Timor
Authors: Bovensiepen Judith , Delgado Rosa Frederico
Published: July 2016

For Catholic missionaries in the early twentieth century, the only way to achieve true conversion of Timorese ancestral ritualists was the deliberate destruction of sacredlulikhouses. Although Timorese allegedly participated enthusiastically in this destruction,lulik(a term commonly translated as sacred, proscribed, holy, or taboo) remains a key part of ritual practice today. This article offers a dynamic historical analysis of what may be described as a particular form of Southeast Asian animism, examining how people's relationships with sacred powers have changed in interaction with Catholic missionaries. It links the inherent ambivalence of endogenous occult powers to religious and historical transformations, teasing out the unintended consequences of the missionaries' attempts to eradicate and demonizelulik. Comparing historical and ethnographic data from the center of East Timor, it argues that, contrary to the missionaries' intentions, the cycles of destruction, withdrawal, and return that characterized mission history ended up strengtheninglulik. Inspired by anthropological studies of “taboo” and “otherness,” especially the work of Mary Douglas and Valerio Valeri, this article makes visible the transformation of the sacred in relation to outside agents: when relations with foreign powers were productive, the positive sides oflulikas a source of wealth and authority were brought out; yet when outsiders posed a threat, the dangerous and threatening aspects oflulikwere accentuated. This analysis allows us to highlight the relational dimensions of sacred powers and their relation to ongoing social transformations.
Battles for the Golden Grain: Paddy Soldiers and the Making of the Northeast India–East Pakistan Border, 1930–1970
Authors: Sur Malini
Published: July 2016

This essay explores the fragmentation of provincial rice fields into warring postcolonial territories in mid-twentieth-century South Asia. I focus on rice as a powerful grain that connected the shifting borders of British colonial Assam and Bengal, and later Northeast India and East Pakistan (1930–1970). I show how state repression and competing claims to rice harvests contended with shifting terrains. At important historical junctures, rice came to link cultivation and territorialization, state violence and food, and dispossession and espionage. I engage with the powerful symbolism attached to rice by colonial and post-colonial officials, border guards, and cultivators who were variously conceived of as peasants andadivasis, as they sought to settle, cultivate, demarcate, and govern new national boundaries in a radically changing landscape. This paper situates rice battles within current discussions on Asia's borderlands to show how rice established the border as a space for alterity and to expose the blurred boundaries between static peasants and mobileadivasis, and between cultivation and soldiering.
FARMER RESEARCH NETWORKS AS A STRATEGY FOR MATCHING DIVERSE OPTIONS AND CONTEXTS IN SMALLHOLDER AGRICULTURE
Authors: NELSON REBECCA , COE RICHARD , HAUSSMANN BETTINA I. G.
Published: July 2016

The agricultural research and development institutions in most developing countries are poorly equipped to support the needs of millions of smallholder farmers that depend upon them. The research approaches taken by these systems explicitly or implicitly seek simple, one-size-fits-all solutions for problems and opportunities that are extremely diverse. Radical change is needed to facilitate the agroecological intensification of smallholder farming. We propose that large-scale participatory approaches, combined with innovations in information and communications technology (ICT), could enable the effective matching of diverse options to the wide spectrum of socio-ecological context that characterize smallholder agriculture. We consider the requirements, precedents and issues that might be involved in the development of farmer research networks (FRNs). Substantial institutional innovation will be needed to support FRNs, with shifts in roles and relationships amongst researchers, extension providers and farmers. Where farmers’ organizations have social capital and strong facilitation skills, such alignments may be most feasible. Novel information management capabilities will be required to introduce options and principles, enable characterization of contexts, manage data related to option-by-context interactions and enable farmers to visualize their findings in useful and intelligible ways. FRNs could lead to vastly greater capacity for technical innovation, which could in turn enable greater productivity and resilience, and enhance the quality of rural life.
A Noblewoman's Changing Perspective on the World: The Habsburg Patriotism of Rosa Neipperg-Lobkowicz (1832–1905)
Authors: Godsey William D.
Published: July 2016

Until not so very long ago, the national conflicts in the last decades of the Habsburg monarchy prompted historians to focus on nationality as the crucial marker of self-understanding among its populations. The high tide of modern nation-states after 1918 made national borders, national mindsets, and national power structures the framework for ever-greater historical interest in the lineages of national genealogy. In recent decades, scholars have questioned the assumption that modern nations were primordial or natural, even as such entities remain a prime object of attention in a world where nation-states and identity politics help define research agendas and nationalism continues to be a potent force. The lines of inquiry have taken a number of directions. First, historians have linked the pervasiveness of nation and national identity to specific historical circumstances. Perhaps most famously, the political scientist Benedict Anderson's insight regarding “imagined communities” pointed up the contingency of modern nations. It was increasingly accepted that they are artificial constructs of relatively recent date and firmly rooted in time and place. The neat boundaries that seemed to define them, as on old ethnographic maps, faded as their elusive, conditional, and shifting contours were recognized.
Will up-scaled forest conservation incentives in the Peruvian Amazon produce cost-effective and equitable outcomes?
Authors: BÖRNER JAN , WUNDER SVEN , GIUDICE RENZO
Published: July 2016

Deforestation and forest degradation in the Peruvian Amazon represent a major threat to biodiversity-related ecosystem services and the global climate. In 2010, the Peruvian Ministry of Environment launched the National Forest Conservation Program for Climate Change Mitigation, an innovative approach to maintaining forest cover of over 54 million hectares of land in protected areas and indigenous and peasant communities. A key component is a payments for environmental services scheme encouraging investments in sustainable land and forest uses in community-controlled territories. We conducted an ex-ante assessment of how the program would play out in terms of conservation cost–effectiveness, income effects and distributional (equity) outcomes if payments were up-scaled, as intended, to all native communities in the Peruvian Amazon. Our spatially explicit impact assessment relied on remotely sensed deforestation data and field data-supported estimates of conservation opportunity costs. We found that the spatially heterogeneous distribution of forestland and economic returns to multiple land uses across communities results in important tradeoffs between hypothetical cost–effectiveness, poverty alleviation and equity outcomes. Nevertheless, our scenario analyses suggested that alternative design options for payment schemes could improve both cost–effectiveness and equity outcomes simultaneously.
The Casualty Actuarial Society and Actuarial Studies in development of Non-Life Insurance in North America
Authors: Longley-Cook L. H.
Published: July 2016

Thank you, Mr. Masterson, Sir George and friends. Mr. Masterson told you that Mr. Longley-Cook was going to give this report originally. Since he can't, he has turned it over to me, and I shall deliver it practically the way he has written it.

The profession of actuary originating in the need for a scientific approach to the problems of early life insurance companies, has broadened its scope over the years, and many actuaries now provide valuable contributions to the scientific study of problems in insurance, commerce and industry which are completely unrelated to life insurance. Because a large majority of actuaries are concerned, however, with problems of life insurance and pension plans, those outside these fields have felt the need for an association which is concerned with their special interests.

I feel most honoured to take part in the birth of Astin, an association for the study of insurance problems outside of the life insurance field. It was most wise that Astin has been formed as a section of the International Congress and not as an independent organization because, although our problems may be different, we will gain much in our mutual association.

A specialist should not, in his devotion to his particular line of study, lose touch with the broader and more general developments of science. Cross-fertilization of ideas can, on many occasions, prove invaluable. It was over 48 years ago that Mr. Stanley Otis and others suggested that a society of actuaries and statisticians of liability companies be formed. Some five years later, the Casualty Actuarial and Statistical Society of America—later to be known by the shorter title of Casualty Actuarial Society—was inaugurated.
Some Numerical Aspects in Transient Risk Theory
Authors: Janssen J. , Delfosse Ph.
Published: July 2016

We give some actual possibilities for computing numerical values in the classical risk models both in transient and asymptotical cases by introducing the concept of normed model. Some recent approximations are tested on numerical examples.

We also emphasize the interest of these methods to compute waiting time distributions (transient and stationary cases) in queueing theory.
A note on the ruin problem for a class of stochastic processes with interchangeable increments
Authors: Grandell Jan , Peiram Lars
Published: July 2016

Models for the risk business of an insurance company are often constructed by weighting pure Poisson models. In this paper it is verified that it is possible to calculate the probability of ruin in such weighted models by weighting ruin probabilities of pure Poisson models.
Numerical evaluation of ruin probabilities for a finite period
Authors: Thorin Olof , Wikstad Nils
Published: July 2016

In this paper the authors remind of the known formulas for the double Laplace-Stieltjes transforms of the ruin probabilities ψ(u, t), where u is the initial risk reserve and t stands for the operational time, in the case of independent interoccurence times and claim amounts such that the interoccurrence times are identically distributed Κ(t), t ≥ o, Κ(o) = o, and the claim amounts are identically distributed P(y), — ∞ < y < ∞. For some cases, where I — P(y) and I — Κ(t) are exponential polynomials, numerical inversions of the said Laplace-Stieltjes transforms are made for a selection of u- and t-values in combination with safety loadings of various sizes and signs. Moreover, some values are given when I — P(y) or I — Κ(t) are of Pareto type and comparisons are made with the results when the Pareto distributions are approximated by suitable exponential polynomials.
Statement of Principles Regarding Property and Casualty Loss and Loss Adjustment Expense Liabilities
Authors:   Committee on Loss Reserves
Published: July 2016

The purpose of this statement is to provide general guidelines for the use of actuaries engaged in the establishment and review of loss and loss adjustment expense reserves. It is a statement of the Casualty Actuarial Society's Committee on loss Reserves. The statement consists of three parts.

1. Definitions

2. Considerations

3. Procedures

The balance sheet of the Fire and Casualty Annual Statement includes liabilities that are not subject to precise valuation. The reserves for unpaid losses (line 1, page 3 of the Annual Statement) and the reserve for unpaid loss adjustment expense (line 2, page 3 of the Annual Statement) cannot be precisely determined in advance. These reserves must be estimated. Because of their relative size and the difficulty in achieving accurate estimates of their values, these liabilities are vitally important balance sheet items. It is important that proper actuarial and statistical procedures be employed in order to improve the likelihood of reliable reserve estimates. Without reliable reserve estimates, an accurate evaluation of the financial condition of a fire and casualty insurer cannot be accomplished.

Loss reserving involves the current financial evaluation of costs associated with future contingent events, a matter of fundamental interest to actuaries. The contingencies involved are those factors which affect the cost of future payments on insured events which have already occurred. As ratemaking is another application of the same estimating process, the actuarial methodology is similar in many respects.

The definitions in the next section apply to both loss reserves and loss adjustment expense reserves.

For the purpose of this statement the terms “loss” and “claim” will be used interchangeably.
Calculation of Provisions Using Credibility Theory
Authors: Cabral M. A. Pereira , Garcia J. M. Afonso
Published: July 2016

The increasing difficulties facing the insurer when he measures certain risks and fundamentaly when that measurement has to be carried out “a priori” are not easily overcome. Thus, the greater part of the insurance companies still use in numerous branches subjective methods of assessing a risk, which unfortunately do not lead to the best results. Especially in certain risks with undefined characteristics, the problem becomes more accentuated to the point of being practically impossible to class risks whose behaviour would be homogeneous.

For example we can analyse the numerous problems of this nature arising in the motor insurance in all countries in assessing the combined risk motor-car and driver.

Numerous solutions have been proposed and amongst them a system of premiums adapted to the actual risk and very especially the credibility premiums represent a fundamental step in the evaluation of these types of risks, for they have an advantage of at least as experience increases assuming an authentic measurement “a posteriori” of the true degree of risk which they cover.
Dynamic Programming, An Approach for Analysing Competition Strategies
Authors: Pentikäinen T.
Published: July 2016

Stochastic-dynamic programming provides a technique for forecasting limits within which the insurance business will flow by a prefixed probability. The future development depends, among numerous other things, on management strategies, especially resources, which are planned for allocation in the acquisition of new business and for competition. This technique can be used to analyse different market situations. Various competitive measures and eventual counteractions by competitors can be assumed and simulated for the purpose. In this way the consequences of different strategies can be studied in order to find the most appropriate one. Our approach is similar to the well-known business games where teams play business in a simulated market. The idea of applying dynamic programming to business games was suggested by Esa Hovinen (discussion at the Astin Colloquium in Washington in 1977).
Recursive Evaluation of a Family of Compound Distributions
Authors: Panjer Harry H.
Published: July 2016

Compound distributions such as the compound Poisson and the compound negative binomial are used extensively in the theory of risk to model the distribution of the total claims incurred in a fixed period of time. The usual method of evaluating the distribution function requires the computation of many convolutions of the conditional distribution of the amount of a claim given that a claim has occurred. When the expected number of claims is large, the computation can become unwieldy even with modern large scale electronic computers.

In this paper, a recursive definition of the distribution of total claims is developed for a family of claim number distributions and arbitrary claim amount distributions. When the claim amount is discrete, the recursive definition can be used to compute the distribution of total claims without the use of convolutions. This can reduce the number of required computations by several orders of magnitude for sufficiently large portfolios.

Results for some specific distributions have been previously obtained using generating functions and Laplace transforms (see Panjer (1980) including discussion). The simple algebraic proof of this paper yields all the previous results as special cases.
On Ordering and Danger of Claim Frequency Distributions
Authors: Goovaerts M. J.
Published: July 2016

The notion of ordering and danger of claim size distributions is extended to claim frequency distributions.
An Application of Credibility Theory to Solvency Margins: Some Comments on a Paper by G. W. De Wit and W. M. Kastelijn
Authors: Henrik Ramlau-Hansen
Published: July 2016

Some comments are given on a recent paper by de Wit and Kastelijn (1980) and alternative methods for analysing loss ratios are proposed in connection with the determination of the necessary solvency margins of non-life insurance companies. The methods are illustrated by a numerical example.
Théorie du bonus: Consequences de L'Etude de Mr. le Professeur Frechet
Authors: Franckx
Published: July 2016

La théorie du bonus n'en est qu'à ses débuts et, afin d'en étudier une première approximation, Monsieur le Professeur Fréchet a utilisé la théorie des chaînes de Markoff-Poincaré; la première synthèse de cette théorie a été donnée dans son livre „Recherches théoriques modernes sur le calcul des probabilités — 2ème livre — Gauthier Villars”.

Nous trouvons que l'idée de Monsieur Fréchet, précisée dans un cadre bien défini d'hypothèses, est particulièrement intéressante et nous voudrions, quant à nous, essayer de dégager pour les actuaires les conséquences qu'une telle hypothèse introduit. On pourra en déduire une marche à suivre pour vérifier dans quelle mesure cette hypothèse cadre avec la réalité.

L'hypothèse fondamentale de Monsieur Fréchet consiste à admettre:

1°) l'existence d'une probabilité pour qu'un véhicule ayant eu i sinistres au cours de l'année calendrier, subisse j sinistres au cours de l'exercice suivant;

2°) que cette probabilité est indépendante de la voiture et de l'année considérée.

Si nous considérons les possibilités réduites à r = 3 cas (de façon à simplifier l'exposé, ce qui ne limite en rien le raisonnement), les possibilités seront complètement définies par le tableau ou matrice de la chaîne de Markoff-Poincaré (voir page suivante).

L'existence d'une chaîne de Markoff-Poincaré entraîne un certain nombre de conséquences, développées et démontrées dans l'ouvrage cité de Monsieur Fréchet.
Reserves of Motor-Vehicle Insurance in Finland
Authors: Pentikäinen Teivo
Published: July 2016

The Ministry of Social Affairs, which acts i.a. as the supervising office in Finland, has given instructions regarding the normal reserves of insurance companies. A summary of these and some comments are given here as far as they concern motor-vehicle insurance. The instructions as far as they concern the subject referred to in the following in the items 2-6, 9 and 10, were compiled by a committee, presided over by Mr. I. Ketola, M. Sc, which availed itself of the experience of several Finnish insurance companies.

In order to give a review of the system as a whole many items, which are mathematically trivial and well-known, are briefly explained.

The conventional principle of “pro rata parte temporis” is followed, which leads to the well-known reserve

where P is the premium income of the company. This provides that the days when the premiums fall due are approximately equally distributed over the year (which can be checked from the premium sums of the different months in the book-keeping) or at least have no cluster points in the second half of the year and that the cost of the collecting of premiums is not less than 0.2 P. A more accurate calculation takes into account i.a. temporary short term policies etc.

In casu-reserve. All unpaid claims (except those mentioned later) due to accidents which occured before the end of the account year, are listed and rated one by one. Doubtful cases, e.g. where the cause of the accident is still under litigation, are calculated in accordance with the “worst” alternative.
Introductory report
Authors: Jansen J. H. C.
Published: July 2016

As reports on work done on subjects discussed at earlier colloquia and on new lines of investigation 6 papers have been laid down on my table (To be exact, 5 on my table and the last one on my chair at the beginning of this colloquium on Wednesday morning).

Four of them deal with problems concerning the estimation of reserves. These are the papers by Beard, Molinaro, Benedikt and Hovinen.

The other two papers, each of which has two authors, namely Kauppi and Ojantakanen and van Klinken and Groenenberg deal with mathematical questions of more general interest.

I can repeat what my colleagues have said this week:

Although the number of the papers is rather small, the importance and the quality of them seem to me to be very great.

The paper of R. E. Beard concerns the studies he has made on the data provided by the 6th Conference of European Insurance Supervisory Services. Suitable statistics of motor insurance on which to experiment have been made available relating to 28 European insurance companies. Beard has made certain preliminary studies of these statistics. His paper has been written against the background of these studies. Although only the broadest indications of numerical values are given, since the detailed statistics are confidential, nevertheless the comments made are based on the studies of the figures. Therefore these comments have a considerable practical utility.

As a basic principle on which to build calculations of technical reserves it is assumed that the claim frequency rate will be constant and that the distribution of claims by amount will be stable, both apart from random fluctuations. Although it is hardly possible to prove the validity of these assumptions, there could be no basis for calculation if these principles were not true.
Estimating incurred claims
Authors: Benedikt V.
Published: July 2016

The problem of estimating the final amount after settlement of Motor and General Third Party claims incurred during an underwriting year is of considerable importance for direct writing companies, as well as for reinsurers. While methods of considerable precision have been proposed for direct writing companies' business (ref. 1,2), a less exact but simpler method, which is applicable, i.a., to non-proportional reinsurance, could also be of interest.

The method uses the so-called “chain relatives” (ref. 3) computed from the figures for incurred losses similar to those quoted on p. 157, ref. 1. The year in which losses Si,j have occurred is designated by the subscript i, whilst the years in which the corresponding amount of losses paid plus outstanding has been ascertained (or estimated) are designated by the subscript j.

“Chain relatives” are defined as a ratio

If the available statistics embrace n years, ai,j can be computed for every j = 1, 2, 3, … n—1 but only for i ≤ n—j. To obtain estimates of ai,j for every i > n—j up to i = n we shall use E(ai,j)for fixed j.

The underlying hypothesis concerning ai,j is that every ai,j consists of a systematic part and of a random part. The random parts can always be assumed to have the mean = 0. For fixed j the systematic parts are a function of the index for the value of money and of several parameters defining the process of claims settlement. The index for the value of money obviously being constant for each fixed j, it is assumed that the other parameters are also constant for fixed j. This, of course, presupposes that the average proportion (over the years of occurrence) of settlement of the incurred losses is independent of their initial volume and of the year of occurrence.
The rescue of an insurance company after ruin
Authors: Borch Karl
Published: July 2016

1.1. In the different versions of the “Theory of Risk” it is almost universally assumed that ruin or bankruptcy marks the end of the game. The earlier versions of the theory tried to estimate the probability of this event, and studied the steps which an insurance company could take to bring probability of ruin down to an acceptable level. The more modern versions of the theory of risk tend to formulate the problem in economic terms, and study the cost of postponing or avoiding ruin.

In a recent discussion of a paper [4] surveying the development of the theory of risk, Professor Bather suggested that ruin may not necessarily be the end. If an otherwise sound insurance company gets into difficulties, so that ruin looms large, it is very likely that steps will be taken to rescue the company, for instance by refinancing, or in more extreme cases, by a merger.

1.2. To practical insurance men the simple suggestion of Professor Bather may seem next to trivial. Insurance companies get into difficulties fairly regularly, and rescue operations are considered in the insurance world, if not daily, at least annualy. The suggestion has, however, far-reaching implications for the theory of risk, and these do not seem to have been fully realised. If ruin does not mean the end of the game, but only the necessity of raising additional money, the current theories of risk may have to be radically revised. In this paper we shall discuss some of these implications.
L'assurance de la propriété de l'état dans la République populaire de Pologne
Authors: Banasinski Antoni
Published: July 2016

1. Le fait que le 8-e Colloque ASTIN a lieu en Pologne donne une bonne occasion pour informer les membres de l'ASTIN sur l'organisation actuelle des assurances dans ce pays qui est d'ailleurs pareille à celle des assurances dans les autres pays socialistes. Dans le présent rapport sera présenté en particulier le problème des assurances du patrimoine national (propriété de l'État) qui comprennent aussi les risques d'assurance importants et complexes.

2. Après la II-e Guerre Mondiale la Pologne a connu de profonds changements sociaux et économiques. La grande et moyenne industries ont été nationalisées. On a réalisé la réforme agraire. Le transport et l'échange des marchandises ont été confiés à des entreprises d'Etat et coopératives. Tout le système financier, y compris les banques et les assurances, a été nationalisé, etc. Actuellement en Pologne les activités d'assurance sont effectuées par deux établissements.

Panstwowy Zakład Ubezpieczeń — en abréviation PZU — (Assurance Nationale Polonaise);

Towarzystwo Ubezpieczeń i Reasekuracji „WARTA” — en abréviation „WARTA” (Compagnie d'Assurances et de Réassurances SA „WARTA”).

3. La PZU ne s'occupe que des assurances du pays, c.á.d. des assurances des objets situés en Pologne et des personnes domiciliées en Pologne.

La „WARTA” s'occupe de toutes assurances extérieures liées aux paiements en devises (contractées pour la plupart en monnaie étrangère), ainsi done avant tout des assurances des marchandises dans le transport maritime, des assurances des moyens de transport maritime et fluvial, des assurances d'aviation, des assurances des véhicules automobiles etc.
Control of a portfolio of insurance Contracts
Authors: Borch Karl
Published: July 2016

1.1. In this paper we shall consider a given portfolio of insurance contracts, and we shall study the following two problems:

(i) How should this portfolio be reinsured?

(ii) What reserves should the company maintain to pay claims which will be made under the contracts in the portfolio?

This means that we shall ignore all questions as to how the company acquired the portfolio, i.e. some of the most important questions concerning management control of insurance companies, such as rating policy, underwriting control etc.

1.2. Even the two simple problems, which are singled out for study in this paper, cannot be solved unless we specify the objectives and the external circumstances of the company.

It is obvious that the reinsurance problem cannot be solved unless we know something about the company's “attitude to risk”, and about the cost of obtaining cover for various kinds of risk in the reinsurance market.

It is also obvious that we cannot solve the reserve problem unless we specify the safety requirements, which the company has to satisfy. We shall see in the following that we may also have to specify the portfolios, which the company expects to underwrite in the future.
Minimum Variance Reinsurance
Authors: Vajda Stefan
Published: July 2016

In a paper entitled “An Attempt to Determine the Optimum Amount of Stop Loss Reinsurance” (XVIth Int. Congr. Act. Bruxelles 1960) Karl Borch has shown that, if the reinsurance premium is given, the smallest variance of the cedent's payments is obtained by a stop-loss reinsurance contract. Paul Markham Kahn, in “Some Remarks on a Recent Paper by Borch”, a paper read to the 1961 Astin Colloquium, has given an elegant proof of this theorem which appears to apply also to cases not considered by Borch. In this paper we study the problem from the reinsurer's point of view and it will be seen that, under natural conditions which are also used in the proof of the Borch-Kahn theorem, the minimum variance of the reinsurer's payments is obtained by a quota contract. This focusses attention on a peculiar opposition of interests of the two partners of a reinsurance contract. However, we do not enter any further into the investigation of a possible resolution of this conflict.

We study a problem concerning the division of risk between a cedent and his reinsurer. The risk may refer to a whole portfolio (in which case one might consider a Stop-Loss contract), or to a single contract (when an Excess-Loss contract is a possibility). We shall here use the nomenclature of a portfolio reinsurance.

Let it be assumed that a function F(x) is known which gives the probability of a total claim not exceeding x. We have then in Stieltjes integral notation

The two partners to a reinsurance arrangement agree that the reinsurer reimburses m(x).x out of a claim of x, where m(x) is a continuous and differentiate function of x and o ≤ m(x) ≤ 1.
A Distribution Free Method for General Risk Problems
Authors: Bühlmann H.
Published: July 2016

In practical applications of the collective theory of risk one is very often confronted with the problem of making some kind of assumptions about the form of the distribution functions underlying the frequency as well as the severity of claims. Lundberg's [6] and Cramér's [3] approach are essentially based upon the hypothesis that the number of claims occurring in a certain period obey the Poisson distribution whereas for the conditional distribution of the amount claimed upon occurrence of such a claim the exponential distribution is very often used. Of course, by weighting the Poisson distributions (as e.g. done by Ammeter [1]) one enlarges the class of “frequency of claims” distributions considerably but nevertheless there remains an uneasy feeling about artificial assumptions, which are just made for mathematical convenience but are not necessarily related to the practical problems to which the theory of risk is applied.

It seems to me that, before applying the general model of the theory of risk, one should always ask the question: “How much information do we want from the mathematical model which describes the risk process?” The answer will be that in many practical cases it is sufficient to determine the mean and the variance of this process. Let me only mention the rate making, the experience control, the refund problems and the detection of secular trends in a certain risk category. In all these cases the practical solutions seem to be sufficiently determined by mean and variance.

Let us therefore attack the problem of determining mean and variance of the risk process while trying to make as few assumptions as possible about the type of the underlying probability distributions. This approach is not original. De Finetti [5] has already proposed an approach to risk theory only based upon the knowledge of mean and variance. It is along his lines of thought, although in different mathematical form, that I wish to proceed.
Formulation Bayesienne du probleme des valeurs extremes en relation à la réassurance en “excedent de sinistres”
Authors: Fürst Dario
Published: July 2016

En matière de détermination de la prime de réassurance en “excédent de sinistres”, nous nous trouvons devant le problème de la distribution des valeurs extrêmes, duquel nous avons déjà une littérature vaste et bien connue, plus particulièrement en ce qui concerne l'allure asymptotique de la distribution qui nous intéresse. Dans cette note on veut indiquer, dans ses grandes lignes, un procédé largement dégagé des résultats de la théorie mentionnée, qui permet un examen de l'influence réciproque entre les hypothèses et la signification des résultats expérimentaux qui est dans l'esprit du procédé par induction.

Pour fixer l'attention sur l'allure asymptotique de la distribution, sans nous occuper de sa forme d'ensemble, nous n'examinerons que la distribution des sinistres qui dépassent une certaine valeur ξ. En particulier, nous pouvons choisir pour cette valeur la limite assignée pour une certaine forme de réassurance; d'ailleurs, on peut penser à un choix arbitraire, ce qui se fera également dans cette note, où elle sera supposée indéterminée à priori, afin que l'on puisse la choisir sur la base des résultats obtenus.

Soit done ξ l'extrême inferieur des sinistres, exprimés en termes monétaires, dont la distribution est à l'étude; et soit F(x;ξ = P(X ≤ x | X ˃ ξ) la fonction de répartition correspondante. En pratique, nous pourrons assumer comme F(x;ξ) une fonction, opportunément simple, qui respecce nos hypothèses dans un voisinage droit suffisamment grand de ξ. Cette précision sera sousentendu par la suite, de sorte que, lorsque nous considérerons le simple exemple concret exposé plus bas, nous devrons tenir compte du fait que la foncion F(x; ξ) considérée n'est qu'une approximation, valide dans un voisinage droit de ξ, de la distribution effective.
Possibilite d'etablir des bases techniques acceptables pour le calcul d'une marge minimum de solvabilite des entreprises d'assurances contre les dommages
Authors: De Mori Bruno
Published: July 2016

La solvabilité d'une entreprise est généralement référée à des vérifications d'ordre patrimonial et financier, à des considérations de nature économique (relatives à l'entreprise en elle-même, à son avenir, au milieu dans lequel elle opère, au marché dont elle constitue une unité élémentaire), à des relèvements, constatations, informations même de caractère subjectif et personnel. En d'autres termes, elle se définit sur la base d'un ensemble d'éléments “réels”, mais aussi de facteurs diversement constitués et diversement déterminés qui consentent, dans leur ensemble, de formuler un jugement, positif ou négatif, dont dérive l'attitude des “tiers” face à la possibilité, plus ou moins large, d'établir ou de développer ou de réduire ou de trancher des rapports contractuels.

Dans le domaine des entreprises d'assurances — à l'égard desquelles l'élément “confiance” de la part du grand public a un poids fondamental, s'agissant d'engagements qui se réalisent dans le temps en fonction de certaines probabilités — le critère de solvabilité n'est pas uniquement basé sur l'ensemble des facteurs d'appréciation indiqués ci-haut, mais trouve un point de répère solide, sur la consistance des “Réserves techniques” (ou, au moins, d'une partie de ces réserves) et sur le contrôle que, dans presque tous les Pays, est exercé par l'Etat en sauvegarde de la “masse des assurés”.
Regards sur le Développement récent de la Théorie du Risque
Authors: Thyrion P.
Published: July 2016

Trois traits caractérisent, me semble-t-il, le développement récent de la théorie du risque et influencent done l'exposé dont notre Président m'a chargé, avec une amabilité tenement pressante que je n'ai pu m'y dérober.

Le temps n'est plus où l'on pouvait déplorer un manque d'intérêt des actuaires pour la théorie du risque: tel est le trait le plus immédiatement évident. ASTIN y a certainement contribué. Le cercle restreint d'adeptes — dirais-je d'initiés — a éclaté. Les idées traversent les frontières et même l'océan. Ce faisant, elles s'enrichissent au passage, se généralisent, ou bien encore rencontrent une idée-soeur qui leur ressemble parfois comme une jumelle mais porte un autre nom. On voit les idées “reςues” se heurter à des conceptions rajeunissantes. On voit aussi les nécessités pratiques infléchir la théorie. Bref il se produit un véritable bouillonnement de recherches et d'applications, des plus heureux pour la théorie du risque, mais des plus pénibles pour le conférencier qui voudrait en cerner convenablement l'évolution. Pour ce faire, l'ampleur et la diversité des publications exigeraient un professionnel en la matière, disposant du temps voulu pour s'informer complètement. Ce n'est pas mon cas et cela explique — et excusera, je l'espère — le cadre délibérément restreint de mon exposé. Car je n'ai pas l'intention de suivre la théorie dans ses multiples démarches réeentes et dans tous ses perfectionnements les plus subtils. Je vous propose plutôt de jeter quelques regards sur le développement récent de la théorie du risque et ainsi de tenter de dégager et d'illustrer quelques idées essentielles sur cette évolution et d'essayer d'entrevoir son déroulement futur. Telles sont les limites de mon objectif.
Note on the Relation Between Compound and Composed Poisson Processes
Authors: Philipson Carl
Published: July 2016

1. In an article on such processes in ASTIN Bull. (II-3, pp. 450–451) the author has derived a relation between cPp i.n.s. (compound Poisson processes in the narrow sense) and composed Poisson processes, which is quite general. In this note this relation shall be simplified under the rather weak condition that Po(t), Pn(t) being the distribution of the number of changes occurring in the interval (o, t), for every fixed value of t, tends to a positive limit less than unity when t tends to infinity.

2. By the theory expounded by Thyrion (Bull, de l'Assoc. Act. Beiges, 1959 and 1963) the characteristic function of the number of events in the interval (o, t) can for each fixed value of t in this case be written

where η is a real variable and i the imaginary unity.

It is easily seen that (1) is equal to the following expression

which has the form of a characteristic function of the number of changes in a composed Poisson process.
On the Calculation of the Ruin Probability for a finite time Period
Authors: Beard R. E.
Published: July 2016

In many risk theoretical questions a central problem is the numerical evaluation of a convolution integral and much effort has been devoted over the years to mathematical and computational aspects. The paper presented to this colloquium by O. Thorin shows the subject to be topical but the present note stems from a recent paper by H. L. Seal, “Simulation of the ruin potential of non-life insurance companies”, published in the Transactions of the Society of Actuaries, Volume XXI page 563.

In this paper, amongst other topics, Seal has presented some simulations of ruin probabilities over a finite time interval. Some years ago (Journal Institute of Actuaries Students' Society, Volume 15, 1959). I pointed out that the form of ruin probability could be expressed as a successive product of values of a distribution function. To my knowledge no one has attempted to see if this product form was capable of development and the numerical values in Seal's paper prompted me to spend a little time on the problem. In the time I had available it has not been possible to do more than experiment, but the conclusions reached may be of interest to other workers in this field. They showed that calculation is feasible but laborious. However, the knowledge that it can be done may suggest methods of improving the techniques.

Seal's first simulation example is the calculation of ruin probabilities when the distribution of the interval of time between the claims is negative exponential and the individual claim distribution is also negative exponential. Instead of following Seal's method we can determine the “gain per interval” and find that if λ is the security loading the frequency function for the gain z is

i.e. a Laplace distribution.
Statistical review of a motor insurance portfolio
Authors: Johnson P. D. , Hey G. B.
Published: July 2016

Motor insurers in the United Kingdom are not subject to Government control over the rating structures they use or the levels of premiums they charge. The market is highly competitive, and each insurer therefore needs to make the best estimate he can of the premium required for each category of risk, to produce a given level of profit. He also needs to estimate the extent to which departures from such premium levels can be justified, for example in order to have a simple rating structure or to meet competition.

The purpose of this note is to give some examples of the statistical tabulations being produced in one insurance office in the United Kingdom. The statistical system which has been developed covers many aspects of motor insurance management, but in this note we shall direct attention to just two, namely

(i) continuous review of the variations in the claims experience from one risk category to another, as a guide to the relative premiums required for the different categories; and

(ii) continuous review of the changing composition of the portfolio and of the movements in and out, to try to assess the extent to which gains and losses of business can be attributed to pricing differences, marketing strategies, etc.
Cumulants of Convolution—Mixed Distributions
Authors: Brown Alan
Published: July 2016

Consider a risk process which is characterised by three stochastic variables

(1) the number of accidents, N,

(2) the number of claims per accident, C, and

(3) the amount of a claim, X.

Let Y be a random variable denoting the total loss in a given period.

Suppose that

and

If Pr represents the probability that exactly r claims occur in the period, then Kupper [4] has shown on certain simplifying assumptions that

where , the probability of exactly r claims in n accidents, is given by

and for γ < n

Further
An Analysis of Claim Experience in Private Health Insurance to Establish a Relation between Deductibles and Premium Rebates
Authors: de Wit G. W. , Kastelijn W. M.
Published: July 2016

Many studies concerning the frequency of claims by size in health insurance are not generally known). A possible explanation of this circumstance could be the fact that in most countries this line of insurance has been brought entirely within the ambit of social insurance. Also from the side of the social insurance very few investigations have been published).

In this paper we will analyse the claim experience (relating, to the calendar year 1972) of a private health insurance business. The data have been subdivided according to three levels of coverage (in increasing order of benefits these are: class III, class IIb and class IIa). The claim payments comprise nursing costs, auxiliary costs and the fees for specialist treatment in and out of the hospital.

We will use the following notations:

Si: claim amount paid for the insured i in one year,

n: number of claims,

v: number of risks (policies insured).

In many instances the premium is simply determined as a level premium. In other words each insured pays the premium p, calculated as follows:

.

Actually we make the assumption that the claims are normally distributed, the parameters of which can be estimated as follows:

which permits the calculation of the premium according to:

.
VON NEUMANN’S CONSISTENCY PROOF
Authors: BELLOTTI LUCA
Published: July 2016

We consider the consistency proof for a weak fragment of arithmetic published by von Neumann in 1927. This proof is rather neglected in the literature on the history of consistency proofs in the Hilbert school. We explain von Neumann’s proof and argue that it fills a gap between Hilbert’s consistency proofs for the so-called elementary calculus of free variables with a successor and a predecessor function and Ackermann’s consistency proof for second-order primitive recursive arithmetic. In particular, von Neumann’s proof is the first rigorous proof of the consistency of an axiomatization of the first-order theory of a successor function.