Contract teachers and student achievement in rural China: evidence from class fixed effects

For schooling to play an important role in the development of human capital, the system of education needs to provide quality education, which among other things requires high‐quality teachers. Facing fiscal constraints and growing enrolments, school systems in developing countries often supplement their teaching staff by hiring contract teachers. However, there is limited evidence on how the effectiveness of these teachers compares to that of civil service teachers. We use a dataset from rural primary schools in western China to estimate the causal effect of contract teachers on student achievement and find that gains in student scores on standardised examinations in mathematics and Chinese are less in classes taught by contract teachers than in classes taught by civil service teachers. The results demonstrate that China's education system needs to focus on producing high‐quality teachers to improve the quality of schooling in its rural education system. The findings imply that educators in developing countries should not only seek to hire increasingly more civil service teachers in rural schools, but they should also identify ways of improving the quality of contract teachers. If efforts to improve teaching can succeed, rural students can learn more, earn higher incomes and contribute more to the productivity of the overall economy.     

Heterogeneity of plural forms: A revised transaction cost approach

Strategies pushing firms to adopt plural forms and the heterogeneity of solutions they endorse have attracted increasing attention. This paper proposes a theoretical framework that combines asset specificity and uncertainty to explain why there are plural forms and focuses on the key role of uncertainty, within a given range of asset specificity, to predict what and when specific types of plural forms should be observed. Propositions derived from this model are tested on an extensive set of cases from the agribusiness sector. The empirical richness of these cases allows going beyond the existing literature, which has essentially focused on franchising.     

Investor Overconfidence in Experimental Asset Markets across Market States

Abstract

This study explores how individual overconfidence adjusts after receiving extreme feedback that either supports or contradicts previous decision-making when buying or selling stocks. We find that highly contradicting feedback causes overconfidence to vanish as confidence declines sharply while supportive signals cause overconfidence to increase. Further evidence suggests that strong feedback impulses are associated with higher investor disagreement, supporting prior hypotheses that investors interpret such impulses differently. We also find that methodologies that measure overconfidence in prediction tasks systematically overstate confidence scores as respondents tend to fail to internalize stated confidence intervals appropriately.     

Die Erhebung personenbezogener Gesundheitsdaten bei Dritten

The recently introduced § 213 VVG is linked to an interesting history and regulates an issues that had been discussed in the insurance industry for some time. In its application § 213 VVG is more particular than regulations by the German data protection act, at least concerning the collection of health data. For the processing and usage of data the regulations of the German data protection act still apply. Time will show whether § 213 VVG will lead to a reconciliation of interests of the insured with those of the insurer. The aforementioned two-week-period for the data survey might be a contribution to achieve this goal.     

Pairs trading with a mean-reverting jump–diffusion model on high-frequency data

This paper develops a pairs trading framework based on a mean-reverting jump–diffusion model and applies it to minute-by-minute data of the S&P 500 oil companies from 1998 to 2015. The established statistical arbitrage strategy enables us to perform intraday and overnight trading. Essentially, we conduct a three-step calibration procedure to the spreads of all pair combinations in a formation period. Top pairs are selected based on their spreads’ mean-reversion speed and jump behaviour. Afterwards, we trade the top pairs in an out-of-sample trading period with individualized entry and exit thresholds. In the back-testing study, the strategy produces statistically and economically significant returns of 60.61% p.a. and an annualized Sharpe ratio of 5.30, after transaction costs. We benchmark our pairs trading strategy against variants based on traditional distance and time-series approaches and find its performance to be superior relating to risk–return characteristics. The mean-reversion speed is a main driver of successful and fast termination of the pairs trading strategy.     

Kompromiss im Solarstreit zwischen EU und China

At the end of July 2013 the photovoltaic (PV) trade conflict between China and the European Union was resolved through a compromise whose key elements are price and quantity undertakings promised by China. A minimum price and a maximum export quantity should help to calm PV markets for the time being. Yet the fundamental disequilibria which led to the trade conflict persist. China needs to address its huge domestic excess capacity by reducing subsidies for PV production while vigorously promoting installation. Industrial countries need to address the mismatch between national PV subsidisation policies and the dynamics of global PV markets. If unresolved, further trade conflicts will be inevitable. In solving their bilateral problems, China and the EU have largely bypassed the WTO regime for conflict resolution, thus further revealing the weaknesses of this regime.