On Hypothesis about the Second Eigenvalue of the Leontief Matrix

If an arbitrarily positive eigenvector is repeatedly premultiplied by a positive matrix, then the result tends towards a unique, positive (Frobenius) eigenvector. Brady has demonstrated that the expected absolute magnitude of the estimate of the second largest eigenvalue of a positive random matrix (with identically and independently distributed entries) declines monotonically with the increasing size of the matrix. Hence, the larger the system is, the faster is the convergence. Molnár and Simonovits examined Brady's conjecture in the case where entries of a stochastic matrix are close to 1/n. We prove this hypothesis for any stochastic and positive matrix.     

Applying free random variables to random matrix analysis of financial data. Part I: The Gaussian case

We apply the concept of free random variables to doubly correlated (Gaussian) Wishart random matrix models, appearing, for example, in a multivariate analysis of financial time series, and displaying both inter-asset cross-covariances and temporal auto-covariances. We give a comprehensive introduction to the rich financial reality behind such models. We explain in an elementary way the main techniques of free random variables calculus, with a view to promoting them in the quantitative finance community. We apply our findings to tackle several financially relevant problems, such as a universe of assets displaying exponentially decaying temporal covariances, or the exponentially weighted moving average, both with an arbitrary structure of cross-covariances.     

Stochastic evolution equations in Banach spaces and applications to the Heath–Jarrow–Morton–Musiela equations

The aim of this paper is threefold. Firstly, we study stochastic evolution equations (with the linear part of the drift being a generator of a \(C_{0}\)-semigroup) driven by an infinite-dimensional cylindrical Wiener process. In particular, we prove, under some sufficient conditions on the coefficients, the existence and uniqueness of solutions for these stochastic evolution equations in a class of Banach spaces satisfying the so-called \(H\)-condition. Moreover, we analyse the Markov property of the solutions.Secondly, we apply the abstract results obtained in the first part to prove the existence and uniqueness of solutions to the Heath–Jarrow–Morton–Musiela (HJMM) equations in weighted Lebesgue and Sobolev spaces.Finally, we study the ergodic properties of the solutions to the HJMM equations. In particular, we find a sufficient condition for the existence and uniqueness of invariant measures for the Markov semigroup associated to the HJMM equations (when the coefficients are time-independent) in the weighted Lebesgue spaces.Our paper is a modest contribution to the theory of financial models in which the short rate can be undefined.     

Niche tourism attributes scale: a case of storm chasing

In spite of the rapid and large growth of niche tourism, and the proliferation of tour operators catering to such markets, limited information is available on the measurement of tour operator attributes that are critical to maximise the experience and needs of their tourists. Thus, a study was conducted to comprehensively evaluate different operational attributes of small storm-chasing tour operators. Findings reveal high internal reliability and utility for this niche market; additional testing is suggested to evaluate such scale among other small niche tourism operators.     

Metrisable assessment of the course of stream-systemic processes in vector form in industry 4.0

Quality & Quantity - The goal of this paper is to present an innovative conception how to use metrisable vector structure of a manufacturing process, based on quantitative relations between the...     

Optimality and efficiency of incomplete split-block designs

In this paper, a balanced incomplete split-block design (BISBD) is shown to be universally optimum for the estimation of the interaction effects with respect to each of the intra-plot stratum estimation and the GLSE. Furthermore, the efficiency factor of an optimal design is investigated.     

Insurance guaranty fund—what good is it?

In this paper, we analyze under which conditions a self-supporting insurance guaranty fund can be beneficial for the policyholders in an incomplete market. Within the analyzed setting, we find out that in general, if existent, the potential advantages from its introduction cannot be fairly divided among the participating insurers. Thereby, we have to expect systematic wealth transfers between the policyholders of different insurance companies. We introduce a framework for utility-based fund charges as a solution to this problem.     

Return labour migration: an exploratory study of Polish migrant workers from the UK hospitality industry

Incoming labour migration represents an important research field, especially in the context of East-Central Europe, a key source region of labour migrants to the tourism and hospitality sectors of many Western economies, including the UK. Surprisingly, return labour migration from the UK to this region has not been systematically examined and yet there is increasing evidence of its significance, especially in light of Brexit. The labour migrant motivations to return and their re-integration experiences back home remain poorly understood. This study adopts a qualitative method of data collection and analysis to explore return migration of the Polish workforce from the UK hospitality sector. Homesickness and educational pursuits are identified as the key drivers. The UK employment experience enhances career prospects of former migrants and yet it largely benefits non-hospitality related sectors of the domestic economy. While the re-integration experiences of former migrants are generally positive and the majority are content with the decision to return, some consider an opportunity to re-migrate.     

Simulated Negotiation Outcomes Through Recommendation Crowding

The goal of the paper is to propose a method for finding outcomes of negotiations of multiple parties with a multi-criteria decision outcomes evaluation. Firstly, the procedure for reduction of continuous set of options to large but finite crowd of compromise recommendations is presented. Next, the crowd is integrated to a single benchmark which is treated as a proposal of artificial auxiliary player called a lone wolf as presented by Kersten and Szapiro (Proceedings of the international conference of the society of systems and science. Budapest, 1987). The strategy of negotiation with this artificial player is proposed to generate a benchmark evaluations scheme for real negotiation. Finally, a multi-agent simulation approach for multi-lateral negotiation process modeling is presented in order to estimate possible negotiation outcomes.