I propose a new measure of common, time-varying tail risk for large cross sections of stock returns. Stock return tails are described by a power law in which the power law exponent is allowed to transition smoothly through time as a function of recent data. It is motivated by asset pricing theory and is estimable via quasi-maximum likelihood. Estimates indicate substantial time variation in sto...

In a distributed system, it is often important to detect the causal relationships between events, where event e1 is causally before event e2 if e1 happened before e2 and could possibly have aaected the occurrence of e2. In this paper we argue that it can be essential to security that a process determine, in the face of malicious attack, how two events are causally related. We formulate attacks ...

In this article, we present a particle filter (PF)-based track-before-detect (PF TBD) procedure for detection of extended objects whose shape is modeled by an ellipse. By incorporating of an existence variable and the target shape parameters into the state vector, the proposed algorithm performs joint estimation of the target presence/ absence, trajectory and shape parameters under unknown nuis...

In this paper, we are concerned with the detection and tracking of a target in TBD context. We propose here an efficient particle filter based on a relevant proposal density justified by radar detection considerations. This filter performs well compared to the classical laws used in the literature, especially in terms of speed of convergence for detection. We also identify a minimum number of p...

We study 6,686 IPOs spanning the period 1981-2005 and find that the new issues puzzle disappears in a Fama-French three-factor framework. IPOs do not underperform in the aftermarket on a risk-adjusted basis and do not underperform a matched sample of non-issuers. IPO underperformance is concentrated in the 1980’s and early 1990’s, and IPO’s either perform the same as the market, or outperform o...

We show that a one-sector real business cycle model with mild increasing returns-toscale and variable capital utilization is able to produce qualitatively realistic business cycles driven solely by aggregate demand shocks. In particular, a positive government spending shock can lead to simultaneous increases in output, consumption, investment, employment, labor productivity and the real wage. O...

While more and more people are relying on social media for news feeds, serious news consumers still resort to well-established news outlets for more accurate and in-depth reporting and analyses. They may also look for reports on related events that have happened before and other background information in order to better understand the event being reported. Many news outlets already create sideb...

Advancements in information and communication technologies have enhanced our possibilities to communicate worldwide, eliminating borders and making it possible to interact with people coming from other cultures like never happened before. Such powerful tools have brought us to reconsider our concept of privacy and social involvement in order to make them fit into this wider environment. It is p...

Methods Four towns and two rural districts of the Republic of Bashkortostan (Russia) were chosen for the questionnaire. The total number of the childhood population was 50442 children under 17 years of age. Totally 43907 children or their parents were examined with the help of the screening questionnaire. The parents were questioned by medical nurses during consulting reception hours, or in kin...

Transition from socialist to capitalist economy led to enormous changes in earnings and employment. In our study a long-horizon descriptive analysis is presented about the major trends, including the last fifteen years of socialism. Education, gender, calendar time, age and vintage effects are separately analyzed. Aggregate (quasi-) panel analysis is used to assess the role of labor demand and ...