Essays on speculative financial bubbles

This thesis contributes to the study of long-run relationships between financial assets. We develop a methodology for testing the hypothesis of co-bubbling behaviour in two series, employing a variant of the stationarity test of Kwiatkowski et al. (1992) which uses a conditional 'wild' bootsrap scheme to control size. We subsequently use our method to test for the presence of co-bubbles in a series of different markets. We look at commodities such as gold and silver and the housing market. There is a plethora of research on the efficacy of unit root tests for detecting explosive rational asset price bubbles. However, the migration of these bubbles and the possibility of co-bubbling behaviour of two series have seldom been researched. In the second chapter of this thesis we apply our model to the commodities market and find that the prices of gold and silver co-bubble in the period following the financial crisis. In the third chapter we investigate the migration of speculative housing bubbles between UK geographic regions. In the third chapter we analyse the co-bubbling relationship between rental and housing prices. We find that an explosive bubble behaviour in rental prices will lead to a bubble behaviour in house prices. The two series co-bubble over a period of time of around two years

Using discrete Darboux polynomials to detect and determine preserved measures and integrals of rational maps

In this Letter we propose a systematic approach for detecting and calculating preserved measures and integrals of a rational map. The approach is based on the use of cofactors and Discrete Darboux Polynomials and relies on the use of symbolic algebra tools. Given sufficient computing power, all rational preserved integrals can be found. We show, in two examples, how to use this method to detect and determine preserved measures and integrals of the considered rational maps.Comment: 8 pages, 1 Figur

Testing for Co-explosive Behaviour in Financial Time Series

This article proposes a test to determine if two price series that each contain an explosive autoregressive regime consistent with the presence of a bubble are related in the sense that a linear combination of them is integrated of order zero. We refer to such a phenomenon as ‘co-explosive behaviour’, and propose a test based on a stationarity testing framework. The test allows the explosive episode in one series to lead (or lag) that in the other by a number of time periods. We establish the asymptotic properties of the test statistic and propose a wild bootstrap procedure for obtaining critical values that are robust to heteroskedasticity. Simulations show that the proposed test has good finite sample size and power performance. An empirical application to detect whether co-explosive behaviour exists among a set of precious and non-ferrous metals is presented

Attitudes towards Cypriot Greek and Standard Modern Greek in London’s Greek Cypriot community

Aim To investigate whether the positive attitudes towards Standard Modern Greek and the mixture of positive and negative attitudes towards Cypriot Greek that have been documented in Cyprus are also present in London's Greek Cypriot community. Approach Unlike previous quantitative works, the study reported in this article was qualitative and aimed at capturing the ways in which attitudes and attitude-driven practices are experienced by members of London's diasporic community. Data and Analysis Data were collected by means of semi-structured, sociolinguistic interviews with 28 members of the community. All participants were second-generation heritage speakers, successive bilinguals in Cypriot Greek and English, and successive bidialectal speakers in Cypriot Greek and Standard Modern Greek. The data were analysed qualitatively (thematic analysis). Findings – Positive perceptions of Standard Modern Greek and mixed perceptions, both positive and negative, of Cypriot Greek are found in the context of London. – As in Cyprus, Standard Modern Greek is perceived as a prestigious, proper and 'correct' variety of Greek. Cypriot Greek, in contrast, is described as a villagey, heavy and even broken variety. – Greek complementary schools play a key role in engendering these attitudes. – Unlike in Cyprus, in the London community, the use of Cypriot Greek is also discouraged in informal settings such as the home. Originality Papapavlou & Pavlou contended that "there are no signs of negative attitudes towards Cypriot Greek [in London]" (2001, p. 104). This research shows this claim to be false. Significance/Implications Negative attitudes towards Cypriot Greek lead to a community-wide preference for the use of Standard Modern Greek in communication with other members of the Greek Cypriot community, which poses a great threat to the intergenerational transmission and maintenance of Cypriot Greek as a heritage language in London

Essays on speculative financial bubbles

This thesis contributes to the study of long-run relationships between financial assets. We develop a methodology for testing the hypothesis of co-bubbling behaviour in two series, employing a variant of the stationarity test of Kwiatkowski et al. (1992) which uses a conditional 'wild' bootsrap scheme to control size. We subsequently use our method to test for the presence of co-bubbles in a series of different markets. We look at commodities such as gold and silver and the housing market. There is a plethora of research on the efficacy of unit root tests for detecting explosive rational asset price bubbles. However, the migration of these bubbles and the possibility of co-bubbling behaviour of two series have seldom been researched. In the second chapter of this thesis we apply our model to the commodities market and find that the prices of gold and silver co-bubble in the period following the financial crisis. In the third chapter we investigate the migration of speculative housing bubbles between UK geographic regions. In the third chapter we analyse the co-bubbling relationship between rental and housing prices. We find that an explosive bubble behaviour in rental prices will lead to a bubble behaviour in house prices. The two series co-bubble over a period of time of around two years

Development of a Tool for the Assessment of Nurses' Attitudes Toward Delirium

Background and Purpose: The prevalence of delirium during hospitalization is high in older patients and there is evidence of staff regarding them as unpopular or a burden. This study aims to develop an instrument examining nurses' attitudes toward patients with delirium. Methods: Stages included (a) content identification, (b) content development, (c) content critique, (e) pilot study with a test–retest reliability, (f) field study consisting of psychometric testing of the internal consistency and construct validity. Results: The Cronbach's alpha was 0.89 and the stability reliability was acceptable. The factor analysis resulted in three factors explaining a total of 56.5% of the variance. hese factors are “beliefs,” “behavior,” and “emotions,” explaining 37.025%, 12.792%, and 5.652% of variance. Conclusions: The Attitude Tool of Delirium (ATOD) is a reliable and valid instrument for the assessment of attitudes toward delirium

Identifying Malicious Behavior in Multi-party Bipolar Argumentation Debates

© Springer International Publishing Switzerland 2016.Lately, several works have analyzed potential uses of argumentation in multi-party debates. Usually, the focus of such works is the computation of a collectively “correct” outcome, a challenging task even when the debate’s users truthfully express their beliefs. This work focuses on debates where some users may exhibit specific types of “malicious” behavior: they may lie (bymaking statements they do not believe to hold) and they may hide valuable information (by not making relevant statements they believe to hold). Our approach is the following: firstly, we define “user attributes” which capture different aspects of a user’s behavior in a debate (how active, how opinionated and how classifiable a user has been); then, we build and test experimentally hypotheses that, from the values of these attributes, can predict whether a user has lied and/or hidden valuable information