Contagious speculative bubbles: a note on the Greek sovereign debt crisis

The Greek sovereign debt crisis of 2009/2010 fostered widespread fears of contagion. We analyzed the danger of contagion by studying to which extent news to speculative bubbles in the Greek equity market spread to the equity markets of Portugal, Ireland, Italy, and Spain. To this end, we estimated a version of the present-discounted value model of equity valuation extended to include a rational stochastic speculative bubble. We then studied cross-country causal links between news to speculative bubbles. We found evidence of causality from Greece to the other countries, but no strong evidence of reversed causality. This finding implies that, as far as equity markets are concerned, movements in speculative bubbles in the Greek equity market may in fact have the potential to spread in a contagious way to the other European countries in our sample

Bactericidal Efficacy of Cold Plasma at Different Depths of Infected Root Canals In Vitro

Objectives: Cold plasma (CP) has been shown to be effective even against multiresistant microorganisms. As previous investigations on the effect of CP in root canals showed promising results, the aim of the present study was to analyze the bactericidal efficacy of CP in different depths of infected dentin. Methods: 32 standardized root canals of human mandibular premolars were infected with Enterococcus faecalis and incubated for one week. Specimens were randomly selected for one of four disinfection methods: control (5mL NaCl), 5mL chlorhexidine (CHX), CP alone (CP), and a combination of 5mL CHX and cold plasma (CHX+CP). CHX was ultrasonically activated for 30s, while cold plasma was used for 60s in the root canals. Dentin samples at depths of 300, 500 and 800 µm were obtained and diluted serially. Colony forming units (CFUs) were counted on agar plates after 24h of incubation. Results: The highest overall logarithmic reduction factors (RF) were obtained from CHX+CP (log RF 3.56 p<0.01; Mann-Whitney U test), followed by CP (log RF 3.27 p<0.01) and CHX alone (log RF 2.65 p<0.01) related to the control. All disinfection methods showed significantly lower CFU counts compared to the control group in 300 µm and 800 µm (both p<0.01, Kruskal-Wallis test). Discussion: The adjuvant use of CP might be beneficial in highly infected root canals to improved disinfection. However, the disinfection effect against Enterococcus faecalis of CP is comparable to ultrasonically activated CHX

Data for: Time-varying risk aversion and realized gold volatility

This file contains the (daily) data for the paper "Time-varying risk aversion and realized gold volatility" by Riza Demirer, Konstantinos Gkillas, Rangan Gupta, and Christian Pierdzioch. The file contains a brief description of the data and links to internet pages where data on risk aversion and economic policy uncertainty can be downloaded

Macroeconomic shocks and the German real estate market: Some stock-market-based evidence

We used a structural vector autoregressive model to study how macroeconomic supply and demand shocks affect the German real estate market. We used a real-estate-based German stock market index to measure developments in the German real estate market. We found that the real-estate-based stock market index increases in the wake of supply shocks. Demand shocks, in contrast, have a transitory depressing effect on the stock-market index. A variance decomposition and a historical decomposition show that movements of the stock-market index represent to a much larger extent the impact of supply than demand shocks

Changes in the international comovement of stock returns and asymmetric macroeconomic shocks

We study whether asymmetric macroeconomic shocks help to explain changes in the international comovement of monthly stock returns in major industrialized countries over the period 1975–2004. Based on a time-varying parameter model, we trace out how the pattern of international comovement of stock returns changed over time. In order to identify asymmetric macroeconomic shocks, we estimate vector-autoregressive models. The results of estimating time-series regression models and panel-data models indicate that changes in the international comovement of stock returns are not systematically linked to macroeconomic shocks

Why do speculative bubbles gather steam? some international evidence

We combined tests for speculative bubbles in stock markets with a crosscountry regression framework to analyse whether economic and institutional variables can be identified that make speculative bubbles in stock markets more likely to occur. The list of variables that we found to have a significant effect on the probability that a speculative bubble arises includes an index of shareholder rights (with a negative sign), the share of assets of foreign-owned banks in total banking assets (with a positive sign) and the ratio of gross private saving to gross private disposable income (with a positive sign)