A note on quadratic forms of stationary functional time series under mild conditions

We study distributional properties of a quadratic form of a stationary functional time series under mild moment conditions. As an important application, we obtain consistency rates of estimators of spectral density operators and prove joint weak convergence to a vector of complex Gaussian random operators. Weak convergence is established based on an approximation of the form via transforms of Hilbert-valued martingale difference sequences. As a side-result, the distributional properties of the long-run covariance operator are established

Rederijkers, Kannenkijkers : drinking and drunkenness in the sixteenth and seventeenth-century Low Countries

This article discusses drinking practices and conceptions of drunkenness in the sixteenth- and seventeenth-century Low Countries from the perspective of the rederijkers or guildsmen who would regularly gather together to practice the vernacular art of rhetoric. The essay surveys the regulations and accounts of the chambers of rhetoric in which these gatherings took place, as well as the literary texts the rederijkers produced (including poetry, songs and theatre plays). It also examines the intersections with contemporary genre painting. The central argument of this paper is that drinking, and even drunkenness, was an essential aspect of rederijker culture and the urban middling groups represented by this culture. This argument nuances the influential thesis of the pervasiveness of a Dutch burgermoraal or bourgeois morality. Even though they created comical caricatures of drunkards, rederijkers indulged in heavy drinking themselves. These guildsmen were well aware of the need for moderation, but their regulations and literary texts go beyond moral didacticism and often reveal double layers and self-parody

Making International Human Rights Protection More Effective: A Rational-Choice Approach to the Effectiveness of Ius Standi Provisions

Empirical research shows that international human rights law is to a large extent ineffective. Individual complaint mechanisms are the only significantly effective enforcement mechanism. Certainly many variables influence the success of enforcement through judicial or quasi-judicial mechanisms but one important variable are provisions of ius standi as they have a gate-keeping function. International human rights law can be rendered more effective if individual victims have both de jure and de facto access to its remedies. This article analyzes the different incentives provided by complaint mechanisms for individuals, groups or NGOs to make use of international human rights bodies. They are such, that an insufficient enforcement of IHRL can be expected.

Locally Stationary Functional Time Series

The literature on time series of functional data has focused on processes of which the probabilistic law is either constant over time or constant up to its second-order structure. Especially for long stretches of data it is desirable to be able to weaken this assumption. This paper introduces a framework that will enable meaningful statistical inference of functional data of which the dynamics change over time. We put forward the concept of local stationarity in the functional setting and establish a class of processes that have a functional time-varying spectral representation. Subsequently, we derive conditions that allow for fundamental results from nonstationary multivariate time series to carry over to the function space. In particular, time-varying functional ARMA processes are investigated and shown to be functional locally stationary according to the proposed definition. As a side-result, we establish a Cram\'er representation for an important class of weakly stationary functional processes. Important in our context is the notion of a time-varying spectral density operator of which the properties are studied and uniqueness is derived. Finally, we provide a consistent nonparametric estimator of this operator and show it is asymptotically Gaussian using a weaker tightness criterion than what is usually deemed necessary

A note on Herglotz's theorem for time series on function spaces

In this article, we prove Herglotz's theorem for Hilbert-valued time series. This requires the notion of an operator-valued measure, which we shall make precise for our setting. Herglotz's theorem for functional time series allows to generalize existing results that are central to frequency domain analysis on the function space. In particular, we use this result to prove the existence of a functional Cram{\'e}r representation of a large class of processes, including those with jumps in the spectral distribution and long-memory processes. We furthermore obtain an optimal finite dimensional reduction of the time series under weaker assumptions than available in the literature. The results of this paper therefore enable Fourier analysis for processes of which the spectral density operator does not necessarily exist

How inter-firm networks influence the development of agglomerations

Non-market interactions are increasingly regarded as key explanations for spatial concentration. Consistently, both innovation and local knowledge spillovers play a central role in recent theories of agglomeration. According to these theories, exchange of localised knowledge gives firms an innovative advantage which results in better economic performance. However, it has turned out to be difficult to open the black box of economies of scale using empirical tests.\ud Since interactions get considerable attention in recent agglomeration theory, social network methods and theory are promising approaches to research spatial agglomerations. Even more so because simultaneously, there is an increasing emphasis on interfirm ties in the network field.\ud The goal of our research is to explore how interfirm networks influence the development of agglomerations. Firstly we provide a review on network and innovation literature in the field of spatial clusters. Secondly, we discuss measurement issues related to networks and innovation and ways to overcome them. Finally, we present preliminary results of our network study among high tech firms in the Dutch region of Twente

Double Poisson Cohomology of Path Algebras of Quivers

In this note, we give a description of the graded Lie algebra of double derivations of a path algebra as a graded version of the necklace Lie algebra equipped with the Kontsevich bracket. Furthermore, we formally introduce the notion of double Poisson-Lichnerowicz cohomology for double Poisson algebras, and give some elementary properties. We introduce the notion of a linear double Poisson tensor on a quiver and show that it induces the structure of a finite dimensional algebra on the vector spaces V_v generated by the loops in the vertex v. We show that the Hochschild cohomology of the associative algebra can be recovered from the double Poisson cohomology. Then, we use the description of the graded necklace Lie algebra to determine the low-dimensional double Poisson-Lichnerowicz cohomology groups for three types of (linear and non-linear) double Poisson brackets on the free algebra in two variables. This allows us to develop some useful techniques for the computation of the double Poisson-Lichnerowicz cohomology.Comment: 42 pages. Final version, to appear in Journal of Algebr

Rock-paper-scissors a new and elegant proof

I provide an elegant proof identifying the unique mixed Nash equilibrium of the Rock-Paper-Scissors game. The proof is based on intuition rather than elimination of cases. It shows that for any mixed strategy other than the one that puts equal probability on each of a player's actions, it holds that this strategy is not a best response to any mixed strategy that is a best response to it.