Correlated Risks: A Conflict of Interest Between Insurers and Consumers and Its Resolution

This contribution starts out by noting a conflict of interest between consumers and insurers. Consumers face positive correlation in their assets (health, wealth, wisdom, i.e. skills), causing them to demand a great deal of insurance coverage. Insurers on the other hand eschew positively correlated risks. It can be shown that insurance contributes to a reduction of their asset volatility only if unexpected deviations of payments from expected value correlate negatively across lines of insurance. Analyzing deviations from trend in aggregate insurance payments, one finds the following for the United States and Switzerland. Private U.S. but not Swiss insurance has a hedging effect for consumers, while both social insurance schemes expose consumers to excess asset volatility. In the insurance systems of both countries, the private component fails to offset deviations in the social component (and vice versa). As to the supply of insurance, cointegration analysis indicates the absence of common trends. Therefore, insurance companies could offer combined policies to the benefit of consumers, hedging their underwriting risks both domestically and internationally.Insurance, Portfolio Theory, International Diversification, Combined Contracts

Life-cycle effects of social security in an open economy: Atheoretical and empirical survey

Conventional wisdom views demographic change as aset of exogenous shocks impinging on social security, with the economy treated as aclosed system. This contribution argues that demographics is nothing but the aggregate of individual decisions, which are influenced by social security. This claim is supported by both theoretical argument and empirical evidence with regard to decisions over the life cycle, ranging from educational effort, marriage, number of children, divorce, retirement, and effort to extend one's life. Distinguishing the effects of contributions and benefits of social security, these feedback relationships are shown to in the main hamper employment and growth, thus undermining the financial viability of today's social security schemes, with increasing openness of the economy ('sglobalization') exacerbating problem

Aspects and Exception Handling: The Case of Explicit Join Points

Several authors have debated the modularity and obliviousness of aspects in AOP and the links between these two notions, noting that obliviousness is not always desirable or achievable. Many proposals have appeared, mainly in the context of AspectJ, to mitigate these issues by restricting upfront, or "inferring" and documenting, where aspects can apply. As pointed out, sacrificing certain facets of obliviousness can not only increase safety but even increase modularity. This paper presents and evaluates a simple extension to AspectJ, consisting in explicit join points (EJPs) which denote potential occurrences of aspects in the base code and enable information passing between base code and aspects. The evaluation takes place in the context of exception handling; by picking up on a recent study of the use of aspects for the same purpose, we quantifg the benefits of our extensions for various common measures of code quality in the context of AOP, such as separation of concerns or coupling

Technical analysis: Novel insights on contrarian trading

We analyze the predictive power of technical analysis with a novel data set based on news sentiment that allows to systematically examine a set of technical analysis indicators over an extensive time period. We do not find much statistically significant relationships with the examined indicators and future asset returns, and we almost do not find any alphas in trading strategies based on technical analysis sentiment. We find evidence for a contrarian-based hypothesis: past market returns and technical analysis sentiment are able to predict future technical analysis sentiment with a negative relationship

The Sisyphus Syndrome in Health Revisited

Health care may be similar to Sisyphus work: When the task is about to be completed, work has to start all over again. To see the analogy, consider an initial decision to allocate more resources to health. The likely consequence is an increased number of survivors, who will exert additional demand for health care. With more resources allocated to health, the cycle starts over again. The objective of this paper is to improve on earlier research that failed to find evidence of a Sisyphus syndrome in industrialized countries. This time, there are signs of such a cycle, which however seems to have faded away recentl

A Cryptographic Look at Multi-Party Channels

Cryptographic channels aim to enable authenticated and confidential communication over the Internet. The general understanding seems to be that providing security in the sense of authenticated encryption for every (unidirectional) point-to-point link suffices to achieve this goal. As recently shown (in FSE17/ToSC17), however, the security properties of the unidirectional links do not extend, in general, to the bidirectional channel as a whole. Intuitively, the reason for this is that the increased interaction in bidirectional communication can be exploited by an adversary. The same applies, a fortiori, in a multi-party setting where several users operate concurrently and the communication develops in more directions. In the cryptographic literature, however, the targeted goals for group communication in terms of channel security are still unexplored. Applying the methodology of provable security, we fill this gap by defining exact (game-based) authenticity and confidentiality goals for broadcast communication, and showing how to achieve them. Importantly, our security notions also account for the causal dependencies between exchanged messages, thus naturally extending the bidirectional case where causal relationships are automatically captured by preserving the sending order. On the constructive side we propose a modular and yet efficient protocol that, assuming only point-to-point links between users, leverages (non-cryptographic) broadcast and standard cryptographic primitives to a full-fledged broadcast channel that provably meets the security notions we put forth