Small-time ruin for a financial process modulated by a Harris recurrent Markov chain

We consider a nonstandard ruin problem where: (i) the increments of the process are heavy-tailed and Markov-dependent, modulated by a general Harris recurrent Markov chain; (ii) ruin occurs when a positive boundary is attained within a sufficiently small time. Our main result provides sharp asymptotics for the small-time probability of ruin, viz., P(sup? _{n≤δ u} S _n ≥u), where {S _n } denotes the discrete partial sums of the process and δ∈(0,1/μ), where μ is the mean drift. We apply our results to obtain risk estimates which quantify, e.g., repetitive operational risk losses or the extremal behavior for a GARCH(1,1) process.     

Risk Aversion,Downside Risk Aversion and Paying for Stochastic Improvements

This paper considers the relationship between risk preferences and the willingness to pay for stochastic improvements. We show that if the stochastic improvement satisfies a double-crossing condition, then a decision maker with utility v is willing to pay more than a decision maker with utility u, if v is both more risk averse and less downside risk averse than u. As the condition always holds in the case of self-protection, the result implies novel characterizations of individuals’ willingness to pay to reduce the probability of loss. By establishing a general result on the correspondence between an individual's willingness to pay, and his optimal purchase of stochastic improvement when there is a given relationship between stochastic improvements and the amount paid for them, we further show that all results on the willingness to pay can be applied directly to characterize the conditions under which a more risk averse individual will optimally choose to buy more stochastic improvement. Generalizations of existing results on optimal choice of self-protection can be obtained as corollaries.     

Strong Increases in Downside Risk Aversion

A ranking of risk preferences is of economic interest insofar as it leads to unambiguous comparative statics predictions, and for this to be the case, the ranking must be a strict partial ordering. The ranking by greater risk aversion meets this demand at the second order, and yields a variety of well-known predictions concerning the effect of greater risk aversion on demands for insurance and risky assets, among many other applications. There has been less success at the third order, where ranking preferences by aversion to downside risk has not produced a strict partial ordering. The problem is that account has not been taken of the fact that an increase in downside risk aversion must induce changes in risk aversion as well. We propose a definition of stronger downside risk aversion that does yield a strict partial ordering by requiring a nested increase in both second- and third-order risk aversion, so that v is more strongly downside risk averse than u if v is more risk averse and more downside risk averse than u. We demonstrate that v being more strongly downside risk averse than u is characterized by v never liking any change in the probability distribution for y that induces a third-order stochastic dominance deterioration in the distribution for u(y). We apply the definition to obtain intuitive comparative statics predictions in the precautionary saving problem, and relate the definition to alternatives proposed in the literature.     

Beyond Risk Aversion: Why,How and What's Next?

Risk attitudes other than risk aversion (e.g. prudence and temperance) are becoming important both in theoretical and empirical work. While the literature has mainly focused its attention on the intensity of such risk attitudes (e.g. the concepts of absolute prudence and absolute temperance), I consider here an alternative approach related to the direction of these attitudes (i.e. the sign of the successive derivatives of the utility function).     

Minimal Hellinger martingale measures of order <Emphasis Type="Italic">q</Emphasis>

This paper proposes an extension of the minimal Hellinger martingale measure (MHM hereafter) concept to any order q≠1 and to the general semimartingale framework. This extension allows us to provide a unified formulation for many optimal martingale measures, including the minimal martingale measure of Föllmer and Schweizer (here q=2). Under some mild conditions of integrability and the absence of arbitrage, we show the existence of the MHM measure of order q and describe it explicitly in terms of pointwise equations in ? ^d . Applications to the maximization of expected power utility at stopping times are given. We prove that, for an agent to be indifferent with respect to the liquidation time of her assets (which is the market’s exit time, supposed to be a stopping time, not any general random time), she is forced to consider a habit formation utility function instead of the original utility, or equivalently she is forced to consider a time-separable preference with a stochastic discount factor.     

Öffentliche Güter mit Versicherungscharakter

Dikes as well as early warning systems against natural disasters are just two examples for pure public goods that serve as an insurance device. Dikes reduce the probability of a loss caused by flooding. Such public goods can be seen as public self-protection. By contrast, early warning systems do not reduce the probability of a loss, but the size of a loss. Hence, such public goods can be seen as public self-insurance. The present paper presents a model which takes these characteristics into account. Conditions for the efficient provision of such public goods are derived. Moreover, we analyze the consequences of a change in income and risk aversion towards the efficient provision level as well as the interaction with private market insurance.     

Enhancement of value investing strategies based on financial statement variables: the German evidence

This paper examines the added-value of combining traditional valuation ratios with each other as well as with some financial statement variables in the German stock markets during the 2000–2015 period. The results show that combination pays off and, moreover, that the benefits of combination are greater in Germany than in most other developed stock markets. Particularly, we find strong evidence of the added-value of using Piotroski’s F-score as a supplementary selection criterion for value stocks as well as for low-accrual stocks. Our results show further that the F-score also boosts the efficacy of other valuation ratios besides the book-to-price ratio. In addition, the inclusion of F-score besides a relative value measure tends to increase the average market equity of portfolio firms. The decomposition of the full-sample-period performance into separate bull- and bear-period performance shows clearly that the better performance of F-score-boosted portfolios is mostly attributable to their outperformance during bearish periods, even though on average, they also generate higher bull-period returns than the comparable value portfolios formed without F-score. The use of F-score as a supplementary criterion also increases the proportion of stocks that earn above-market-average returns during the subsequent holding period. For the first time in the financial literature, we also document a strong relationship between high F-score stocks and momentum stocks.     

Tests of investor learning models using earnings innovations and implied volatilities

This paper investigates alternative models of learning to explain changes in uncertainty surrounding earnings innovations. As a proxy for investor uncertainty, we use model-free implied volatilities; as a proxy for earnings innovations, representing signals of firm performance likely to drive investor perceptions of uncertainty, we use quarterly unexpected earnings benchmarked to the consensus forecast. We document that uncertainty declines on average after the release of quarterly earnings announcements and this decline is attenuated by the magnitude of the earnings innovation. This latter result is consistent with models that incorporate signal magnitude as a factor driving changes in uncertainty. Most important, we document that signals deviating sufficiently from expectations lead to net increases in uncertainty. Critically, this result suggests that models allowing for posterior variance to be greater than prior variance even after signal revelation [e.g., regime shifts in Pastor and Veronesi (Annu Rev Financ Econ 1:361–381, 2009)] better describe how investors incorporate new information.     

Effects of Health and Longevity on Financial Risk Tolerance

We investigate the effects of health and life expectancy on tolerance of financial risk. Using a standard life-cycle model, we find that the effects of health and life expectancy on preferences over lifetime-income risk are theoretically ambiguous. However, risk tolerance is independent of health and life expectancy when utility takes one of the standard (harmonic absolute risk aversion) functional forms or when optimal consumption is constant over time. Our empirical results, using data from a stated-preference survey (n=2,795), suggest that financial risk tolerance is positively associated with both health and life expectancy; hence utility is not consistent with standard functional forms.     

Zur Geschichte der Versicherungsmathematik an der TU Dresden bis 1945

In 1919 the chair for Insurance Mathematics has been founded at the TH Dresden.Paul Eugen Boehmer was the first professor at this chair. For a long time this was the only chair in whole Germany which has been completely dedicated to the Insurance Mathematics. It has been preceded by a Seminar on Insurance Mathematics which has been founded in 1896 and has been chaired byGeorg Helm, the professor for Applied Mathematics. The seminar was based on Dresden’s long tradition in Mathematical Statistics and Theory of Probability, National Economy and Insurance Matters. This tradition is connected with the names of the professorsSchloemilch, Huels-se, Zeuner, andBoehmert. The background was the development of Insurance Matters in the economically strong Saxonia.     

Welfare effects of insurance contract non-performance

Non-performance lies at the heart of much of the regulation that insurance companies face. Consumers’ concerns about non-performance of the insurance provider have also been cited as a possible explanation for low demand of microinsurance. We provide a behavioral evaluation of the welfare effects of non-performance risk. We test the hypothesis that the presence of non-performance risk negatively impacts not just take-up of insurance but more importantly the welfare of the insured. We also test if violations of the reduction of compound lotteries axiom could drive this decrease in take-up and welfare. The results show that the compound risk characteristic of non-performance risk does not significantly decrease the welfare of insurance choices made by individuals. This counter-intuitive result is sensitive to the structural modeling of risk preferences. If one assumes the reduction of compound lotteries axiom does characterize behavior towards risk, one finds evidence that non-performance risk reduces welfare for the insured. But if one correctly allows for violations in that axiom in the representation of risk preferences, which is appropriate if one is going to test for the effect of compound risk from non-performance, then the counter-intuitive result is obtained. Take-up is not a reliable proxy for welfare, and the behavioral drivers of take-up are again not the same drivers of welfare. These results provide structural behavioral insight to inform normative policy design with respect to insurance regulation.     

Choices of savings options related to trust in banks’ competence,benevolence and stability

The study investigates whether beliefs in professional investor skill in conjunction with trust in banks and other fund managers explain choices of options for long-term savings. From questionnaire data obtained for a population-based sample (n=178) and a sample of undergraduates (n=186), two index measures were constructed, one of beliefs in the skill of professional investors and another of trust in fund managers. The trust index was aggregated for the three interrelated components: competence, benevolence and stability. Regression analyses of the likelihood of savings in an actively managed fund showed an expected effect of investor-skill beliefs that was mediated by trust in the fund manager. In addition, self-reported knowledge played a larger role than trust for choices of passively managed index funds and in particular for own investment in stocks.     

Variables influencing the customer relationship management of banks

Banks are important role players to the economy of any country. However, to survive in a competitive business environment banks need to focus on building and maintaining client relationships and to identify how their employees influence these relationships. This study investigates the influence of variables, with regard to bank employees, on the customer relationship management (CRM) of banks. A literature study explains CRM, the banking industry and employees' involvement with banking clients. To assess the impact of the predetermined variables from literature on the CRM of banks, a number of hypotheses were constructed and tested empirically among a sample of banking clients. The findings reveal that the variables knowledgeability and attitude of bank employees have a statistically significant impact on the effectiveness of the CRM strategies of banks. Based on the findings of the empirical investigation, strategies are provided for banks to improve their employees' knowledgeability and attitude in order to ensure more effective CRM strategies.     

Shadow prices,fractional Brownian motion,and portfolio optimisation under transaction costs

The present paper accomplishes a major step towards a reconciliation of two conflicting approaches in mathematical finance: on the one hand, the mainstream approach based on the notion of no arbitrage (Black, Merton & Scholes), and on the other hand, the consideration of non-semimartingale price processes, the archetype of which being fractional Brownian motion (Mandelbrot). Imposing (arbitrarily small) proportional transaction costs and considering logarithmic utility optimisers, we are able to show the existence of a semimartingale, frictionless shadow price process for an exponential fractional Brownian financial market.     

Quadratic minimization with portfolio and terminal wealth constraints

We address a problem of stochastic optimal control drawn from the area of mathematical finance. The goal is to minimize the expected value of a general quadratic loss function of the wealth at close of trade when there is a specified convex constraint on the portfolio over the trading interval, together with a specified almost-sure lower-bound on the wealth at close of trade. We use a variational approach of Rockafellar which leads naturally to an appropriate vector space of dual variables, a dual functional on the space of dual variables such that the dual problem of maximizing the dual functional is guaranteed to have a solution (i.e. a Lagrange multiplier) when a simple and natural Slater condition holds for the terminal wealth constraint, and obtain necessary and sufficient conditions for optimality of a candidate wealth process. The dual variables are pairs, each comprising an Itô process paired with a member of the adjoint of the space of essentially bounded random variables measurable with respect to the event \(\sigma \)-algebra at close of trade. The necessary and sufficient conditions are used to construct an optimal portfolio in terms of the Lagrange multiplier. The dual problem simplifies to maximization of a concave function over the real line when the portfolio is unconstrained but the terminal wealth constraint is maintained.     

Quadratic minimization with portfolio and intertemporal wealth constraints

We address a problem of stochastic optimal control motivated by portfolio optimization in mathematical finance, the goal of which is to minimize the expected value of a general quadratic loss function of the wealth at close of trade when there is a specified convex constraint on the portfolio, together with a specified almost-sure lower-bound on intertemporal wealth over the full trading interval. A precursor to the present work, by Heunis (Ann Financ 11:243–282, 2015), addressed the simpler problem of minimizing a general quadratic loss function with a convex portfolio constraint and a stipulated almost-sure lower-bound on the wealth only at close of trade. In the parlance of optimal control the problem that we shall address here exhibits the combination of a control constraint (i.e. the portfolio constraint) together with an almost-sure intertemporal state constraint (on the wealth over the full trading interval). Optimal control problems with this combination of constraints are well known to be quite challenging even in the deterministic case, and of course become still more so when one deals with these same constraints in a stochastic setting. We nevertheless find that an ingenious variational approach of Rockafellar (Conjugate duality and optimization, CBMS-NSF series no. 16, SIAM, 1974), which played a key role in the precursor work noted above, is fully equal to the challenges posed by this problem, and leads naturally to an appropriate vector space of dual variables, together with a dual functional on the space of dual variables, such that the dual problem of maximizing the dual functional is guaranteed to have a solution (or Lagrange multiplier) when the problem constraints satisfy a simple and natural Slater condition. We then establish necessary and sufficient conditions for the optimality of a candidate wealth process in terms of the Lagrange multiplier, and use these conditions to construct an optimal portfolio.     

An enlargement of filtration formula with applications to multiple non-ordered default times

In this work, for a reference filtration \(\mathbb {F}\), we develop a method for computing the semimartingale decomposition of \(\mathbb {F}\)-martingales in a specific type of enlargement of \(\mathbb {F}\). As an application, we study the progressive enlargement of \(\mathbb {F}\) with a sequence of non-ordered default times and show how to deduce results concerning the first-to-default, \(k\)th-to-default, k-out-of-n-to-default or all-to-default events. In particular, using this method, we compute explicitly the semimartingale decomposition of \(\mathbb {F}\)-martingales under the absolute continuity condition of Jacod.     

Mobile banking innovators and early adopters: How they differ from other online users?

The rapid pace of technological development has created opportunities for financial service providers to offer their services via multiple electronic channels. The mobile phone is one of the most promising but so far marginally adopted channel for using financial services by consumers. Earlier literature on innovation adoption argued that those among the first to adopt new innovations possess unique characteristics compared to the majority of consumers. This paper aims to study how mobile banking innovators and early adopters differ from other users of online banking services. An internet survey was conducted among customers of a large Scandinavian bank in Finland yielding 2,675 responses. Logistic regression was used to identify variables differentiating between users of mobile banking and other online banking services. Somewhat contradictory to earlier findings the results indicate that only age (p<0.0005) and gender (p=0.010) differentiate these two groups of customers, while education (p=0.957), income (p=0.624), occupation (p=0.596) and size of the household (p=0.151) were found to be insignificant in differentiating the groups. The results offer service providers better knowledge of the typical mobile banking user thus adding value to their marketing actions in the field of electronic banking.     

Online banking services: a meta-analytic review and assessment of the impact of antecedents and consequents on satisfaction

This paper provides a meta-analysis of the generalizations in the relationships between the antecedents and consequents of satisfaction with online banking services. In total, 118 observations were analysed, with a sample of 49,607 respondents in 39 published articles from studies indexed in ten databases (Jstor, Emerald, PsycINFO, Taylor & Francis, Elsevier Science Direct, Scopus, ProQuest, SciELO, Google Scholar and EBSCO). Specifically, for the data analysis, we used the correlation coefficient r (plus χ², f test, t test, z test and β values). The results showed that constructs related to uncertainty, as evoked by online devices, system performance, quality of device content and online banking device structures, are significant and positive antecedents of consumer satisfaction. We also found that satisfaction with online banking services promotes trust and loyalty. Finally, we also detected that the relationship between reliability, satisfaction and service quality is stronger among Western banking consumers.     

Impact of website characteristics on relationship quality: a comparison of banks financial cooperatives

This study seeks to investigate differences exhibited by bank customers and members of financial cooperatives respecting website characteristics (website design, convenience, information quality, ease of use and security/confidentiality) and their impact on online relationship quality (composed of trust, commitment and satisfaction). An online survey was conducted with 476 banking sector customers (banks and financial cooperatives), followed by a confirmatory factors analysis and multigroup analysis using EQS 6.2 software. Results evidence a significant difference in terms of website design and security/confidentiality. The impact of these variables on relationship quality proves significantly higher in the case of banks. This study submits that web strategies used by banks and financial cooperatives to develop online relationship quality may vary based on the type of organization.