Power and Bipower Variation with Stochastic Volatility and Jumps

This article shows that realized power variation and its extension,realized bipower variation, which we introduce here, are somewhatrobust to rare jumps. We demonstrate that in special cases,realized bipower variation estimates integrated variance instochastic volatility models, thus providing a model-free andconsistent alternative to realized variance. Its robustnessproperty means that if we have a stochastic volatility plusinfrequent jumps process, then the difference between realizedvariance and realized bipower variation estimates the quadraticvariation of the jump component. This seems to be the firstmethod that can separate quadratic variation into its continuousand jump components. Various extensions are given, togetherwith proofs of special cases of these results. Detailed mathematicalresults are reported in Barndorff-Nielsen and Shephard (2003a).     

Introduction

Journal of Productivity Analysis -     

Food Demand Characteristics in Uganda: Estimation and Policy Relevance

Uganda was highly successful in reducing poverty over the past two decades but made little progress towards household food security. This underlines the need for designing food security interventions customised for household‐specific needs and behaviours. This study estimates Ugandan household demand behaviour with a focus on food consumption paying particular attention to household‐specific characteristics. The results show that preferences to increase calorie‐dense staple consumption, likely associated with food energy deficiency, extend far beyond the percentage of rural Ugandans officially deemed poor. Price elasticities indicate that poor rural households are largely well positioned to compensate staple price increases by substitution as long as they are not already concentrated on the cheapest foods. This flexibility applies less to urban households. The estimated demand elasticities generally vary widely between rural and urban households and depend on expenditure levels. Household‐specific characteristics have significant, sometimes pronounced, influences on demand, as do seasons and regions. The results reflect highly differentiated demand behaviour, which can be utilised to improve the design and evaluation of food security interventions.     

Islands in the stream? The challenges and resilience of the Danish industrial relations model in a liberalising world

Nordic industrial relations models have often been highlighted as being successful ‘highroads’ in advanced capitalism. However, the economic crisis has increased pressures to liberalise and deregulate labour markets. Although this challenges the Danish industrial relations model, there are several countermeasures, in particular strong unions and the supportive institutional context, which have prevented erosion indicating the resilience and adaptability of the model.     

Will Economic Partnership Agreements Increase Poverty? The Case of Uganda

Economic Partnership Agreements (EPAs) between the EU and African Caribbean and Pacific countries are frequently criticized because of fears about negative implications for economic development. Using Uganda as a case study, this paper employs an integrated computable general equilibrium‐microsimulation model framework rich in household‐level detail to assess the consequences of the East African Community EPA for economic output and poverty in Uganda. Simulations of the agreement's tariff liberalization provisions indicate a very small negative economic impact and ambiguous outcomes for poverty. The poverty results depend in size and sign on the poverty line, on the way the government addresses tariff revenue losses and on labor market assumptions.     

Social Media Activities of Political Communication Practitioners: The Impact of Strategic Orientation and In-Group Orientation

The question of why political communication practitioners use social media for strategic political communication activities has rarely been investigated. By using well-established theoretical approaches of communication research, such as the influence of presumed influence approach, this study sought to determine the extent to which the subjective perceptions of German political communication practitioners explain their professional social media activities. The results of a survey (N = 1,067) indicate that the more political communication practitioners perceived that other political communication practitioners used and were influenced by Facebook and Twitter, the more often they used social media themselves. In contrast, the presumed reach of Facebook and Twitter among politicians, journalists, and citizens, as well as the presumed influence of both media on these groups, were not related to the practitioners’ social media activities. These findings suggest that the practitioners’ social media activities are driven more by an in-group orientation toward their colleagues and less by a strategic orientation toward external stakeholders.     

Impact of EU agricultural policy on developing countries: A Uganda case study

Despite substantial reforms, the European Union (EU)'s Common Agricultural Policy (CAP) is still criticised for its detrimental effects on developing countries. This paper provides updated evidence on the impact of the CAP on one developing country, Uganda. It goes beyond estimating macrolevel economic effects by analysing the impacts on poverty. The policy simulation results show that eliminating EU agricultural support would have marginal but nonetheless positive impacts on the Ugandan economy and its poverty indicators. From the perspective of the EU's commitment to policy coherence for development, this supports the view that further reducing EU agricultural support would be positive for development.     

Testing the central market hypothesis: a multivariate analysis of Tanzanian sorghum markets

The central market hypothesis is important in the analysis of market integration because it implies a specific market structure while avoiding a simultaneity problem. However, despite its importance, the central market hypothesis is difficult to test and is therefore often assumed. This article shows that the hypothesis can be tested in a Johansen cointegration test provided that prices are nonstationary. This approach is applied to reveal the existence of central markets for sorghum in Tanzania. The results indicate that the Tanzanian sorghum market can be grouped into two market regions, with prices being determined in a central market in each region.     

Economic and environmental analysis of buffer zones as an instrument to reduce ammonia loads to nature areas

In this paper, we present a Danish case study of the effectiveness and costs of protecting nitrogen poor nature areas vulnerable to ammonia eutrophication by appointing buffer zones around them. Buffer zones are found to be an important step towards sustainable co-existence of intensive livestock production and nature conservation when local sources are important contributors to eutrophication. Depending on the deposition patterns, buffer zones may be cost-effective compared to re-establishment of eutrophicated locations, but a need for further model analysis is also identified.     

Estonia’s monetary integration into EMU

Estonia is not only striving for rapid acceptance into the European Union, but it is also directing efforts towards being integrated into EMU without delay. The following article first comments on the extent to which the convergence criteria, as the central precondition for admittance to EMU, have been fulfilled. It then proceeds to discuss the compatibility of Estonia’s present currency board system with the requirement of its participation in the ERM II. Finally, it looks into the consequences of a premature subjection to the ECB’s monetary strategy.