This article investigates market reactions to major United States Department of Agriculture announcements during non-trading and trading hours in the soybean futures market using microstructure data. Following report release, volume increases and remains elevated for up to 15 to 20 minutes. The volume spikes for the non-trading releases relative to the trading releases, but are identical after the first reaction. Report releases during non-trading hours cause a large spike in volatility at the onset of trading which subsides quickly. In contrast, releases during trading hours result in a smaller volatility spike, which extends for 5–6 min at a higher magnitude. Adjusting volatility by normal trading volatility indicates that volatility in trading hour release is higher in both immediate response and persistence. Return correlations provide little evidence to support systematic under- or overreaction in prices regardless of when the report is released reflecting the efficiency of the market. 相似文献
In light of the growing national priority to develop and revitalise entrepreneurship in emerging economies, our understanding of barriers to serial entrepreneurship (SE) in such a context warrants further scholarly attention. Using insights from Ghana, an integrated framework of endogenous and exogenous barriers to SE is advanced. The study identified factors such as stigmatisation of business failure, fear of failure, successive governments’ suspicion of the private sector and lack of a clear national policy as barriers to the development of SE. By creating conditions for de-stigmatising of failure, countries would be able to create conditions for more serial entrepreneurs to emerge and flourish. The analysis also indicates that reinvigorating entrepreneurship by providing space and opportunity for failed entrepreneurs to re-emerge would enable such countries to enhance entrepreneurial activities and improve economic development. The implications for technology analysis and strategic entrepreneurship literature are identified and examined. 相似文献
This paper investigates whether momentum trading strategies are profitable in the Hong Kong stock market, and examines the sources of such profitability. Momentum portfolios are significantly profitable in the intermediate term in Hong Kong, but the profits become insignificant after risk adjustment by the Chordia and Shivakumar (2001) model. The stock-specific return strategy and factor-related return strategy are analyzed to examine which portion of the total return causes stocks to enter extreme portfolios. The Chordia and Shivakumar factor-related return strategy obtains profits with a magnitude that is close to that which is attained by the total return momentum strategy. Additional evidence further supports the view that the Chordia and Shivakumar model captures momentum profits. 相似文献
This paper contrasts the time‐series properties of aggregate and disaggregate UK inflation. While aggregate inflation is found to be non‐stationary, unit root rejection frequencies are increasing when we use more disaggregate data. Structural break analysis suggests that structural shifts in monetary policy could alter inflation persistence. Additionally, panel evidence indicates that the unit root hypothesis can be rejected for sectoral inflation rates. Finally, we compare the persistence properties of UK inflation, finding statistically significant differences between aggregate and disaggregate series. Our analysis suggests that aggregation matters, which has important implications for econometric analysis and the conduct of monetary policy. 相似文献
Understanding the emergence of innovation systems is recently put central in research analysing the process of technological change. Especially the key activities that are important for the build up of an innovation system receive much attention. These are labelled ‘functions of innovation systems’. This paper builds on five empirical studies, related to renewable energy technologies, to test whether the functions of innovation systems framework is a valid framework to analyse processes of technological change. We test the claim that a specific set of functions is suitable. We also test the claim made in previous publications that the interactions between system functions accelerate innovation system emergence and growth. Both claims are confirmed. 相似文献
Background: Validation of overall survival (OS) extrapolations of immune-checkpoint inhibitors (ICIs) during the National Institute for Health and Care Excellence (NICE) Single Technology Assessment (STA) process is limited due to data still maturing at the time of submission. Inaccurate extrapolation may lead to inappropriate decision-making. The availability of more mature trial data facilitates a retrospective analysis of the plausibility and validity of initial extrapolations. This study compares these extrapolations to subsequently available longer-term data.
Methods: A systematic search of completed NICE appraisals of ICIs from March 2000 to December 2017 was performed. A targeted search was also undertaken to procure published OS data from the pivotal clinical trials for each identified STA made available post-submission to NICE. Initial Kaplan-Meier curves and associated extrapolations from NICE documentation were extracted to compare the accuracy of OS projections versus the most mature data.
Results: The review identified 11 STAs, of which 10 provided OS data upon submission to NICE. The extrapolations undertaken considered parametric or piecewise survival models. Additional data cut-offs provided a mean of 18 months of OS beyond the end of the original data. Initial extrapolations typically under-estimated OS from the most mature data cut-off by 0.4–2.7%, depending on the choice of assessment method and use of the manufacturer- or ERG-preferred extrapolation.
Conclusion: Long-term extrapolation of OS is required for NICE STAs based on initial immature OS data. The results of this study demonstrate that the initial OS extrapolations employed by manufacturers and ERGs generally predicted OS reasonably well when compared to more mature data (when available), although on average they appeared to underestimate OS. This review and validation shows that, while the choice of OS extrapolation is uncertain, the methods adopted are generally aligned with later-published follow-up data and appear appropriate for informing HTA decisions. 相似文献
We evaluate whether financial openness leaves emerging market economies vulnerable to the adverse effects of capital reversals (“sudden stops”) on domestic investment. We investigate this claim in a broad sample of emerging markets during the period 1976–2002. If the banking sector does not experience a systemic crisis, sudden stop events fail to have a significant impact on investment. Bank crises, on the other hand, have a significant negative effect on investment even in the absence of a contemporaneous sudden stop crisis. We also find that openness to capital flows worsens the adverse impact of banking crises on investment. Our results provide statistical support for the policy view that a strong banking sector which can withstand the negative fallout of capital flight is essential for countries that open their economies to international financial flows. 相似文献
The European Treaty supports the application of the polluter pays principle in all environmental policies including the Water
Framework Directive. This paper assesses the efficiency of water-charging systems in two European regions. The regions examined
are the South west region of Ireland and the Navarre region in Spain which were selected because they are similar in terms
of economic indicators but different in terms of water pricing structures. The paper describes the development and application
of a simple model to analyse data on water-charging systems from these two regions. We present the results of a detailed scenario-based
investigation illustrating the differences between experience, composition and basis, impact and constraints on the application
of water charges for both regions. The key findings are that existing water charges do not provide incentives for users to
use water efficiently and thereby do not contribute effectively to the environmental objectives of the Water Framework Directive. 相似文献
Using a small empirical model of inflation, output, and money estimated on U.S. data, we compare the relative performance of monetary targeting and inflation targeting. The results show monetary targeting to be quite inefficient, yielding both higher inflation and output variability. This is true even with a nonstochastic money demand formulation. Our results are also robust to using a P∗ model of inflation. Therefore, in these popular frameworks, there is no support for the prominent role given to money growth in the Eurosystem's monetary policy strategy. 相似文献