Optimal Harvesting of an Age-Structured Schooling Fishery

Biologists have criticized traditional biomass models in fishery economics for being oversimplified. Biological stock assessment models are more sophisticated with regard to biological content, but rarely account for economic objectives. This study includes a full age-structured population model for studying schooling fisheries and extends the delayed difference approach used in earlier studies. We take the total harvest as the choice variable, resulting in a simple analytical structure. The model produces optimal steady states that may be higher or lower compared to the delayed-difference formulation. The model is applied to the Baltic sprat fishery. Both ecological and harvesting cost data support specifying Baltic sprat as a schooling fishery. Given nonlinear harvesting costs, the optimal solution is a path toward a steady state with smooth annual harvest and population age structure. Sensitivity analysis shows that the optimal solution is highly dependent on the population level of the sprat’s main predator Baltic cod. A linear cost function and an interest rate below 9 % imply pulse fishing instead of smooth continuous harvesting. Given nonlinear harvesting cost, the optimal steady state yield is rather insensitive to changes in the interest rate. However, under a high cod scenario, interest rates of 10 % or higher implies that no optimal steady state exists.     

Model-independent bounds for option prices—a mass transport approach

In this paper we investigate model-independent bounds for exotic options written on a risky asset using infinite-dimensional linear programming methods. Based on arguments from the theory of Monge–Kantorovich mass transport, we establish a dual version of the problem that has a natural financial interpretation in terms of semi-static hedging. In particular we prove that there is no duality gap.     

Poverty and the shadow economy: The role of governmental institutions

This paper examines the impact of poverty on the size of the shadow economy using cross-country panel data for over 100 countries for the period 1991–2015. The results show that poverty has a positive and significant effect on the size of the shadow economy. Furthermore, we argue that the quality and size of governmental institutions matter in moderating the impact of poverty on the shadow economy. Considering the interactions between poverty and government quality and size, we find that poverty has the largest effect on the size of the shadow economy when government quality is the lowest and the size of the government is the largest. These results withstand a battery of robustness checks.     

Radicalness of blockchain: an assessment based on its impact on the payments industry

Blockchain is receiving considerable attention among practitioners and academics. However, a detailed analysis investigating how the impact of blockchain is going to unfold is still missing. Our article sets out to assess the radicalness of blockchain at an early stage of its development and substantiates the analysis with evidence from the payments industry. We start by distilling five key aspects of radical innovation from extant literature. Our analysis of blockchain then focuses on the payments industry, which represents a major business field of banking and the cradle of this technology. The results of a Delphi study provide 17 statements about the current development of blockchain. The statements deliver insights into the impact of blockchain on the payments industry and reveal the radicalness of the technology. Based on these insights, we investigate how blockchain affects the five key aspects of radical innovation and develop contributions from an innovation management’s perspective.     

The advantages of a small European Monetary Union

The question whether European Monetary Union should include all the EC countries from the start or should initially be limited to a few core countries is again being discussed more intensely. What advantages would a small EMU have from an economic point of view? Which countries should be its founder members?     

Origins of reform resistance and the Southern European regime

With a particular interest for Southern Europe, this contribution develops a classification of obstacles to economic policy reforms. This classification covers approaches ranging from classical economics and political-economic explanations to more innovative explanations linked to behavioral economics. The subsequent part analyzes qualitatively and quantitatively to which extent the “Southern European regime” may imply a particular relevance of some of the potential reform obstacles classified before. We derive “reform ability profiles” which quantify several of the reform obstacles (or reform drivers) to compare EU countries in their likely reform predisposition. These profiles confirm particular Southern European weaknesses which tend to reduce the political-economic feasibility of long-term reforms: a low effectiveness in poverty protection, high intertemporal discounting and uncertainty avoidance, a poor information level of the population and deeply shattered trust in national institutions. In a microeconometric analysis based on Eurobarometer survey data, the analysis leaves the highly aggregated level and looks into the individual heterogeneity in reform acceptance. It is shown that several of the reform obstacles identified in theory are also empirically correlated with the individual inclination to accept reforms.     

Verantwortlich Organisieren

Gute Organisation als Wert — Der barmherzige Samariter aus der Bibel leistet nicht nur die Erstversorgung eines überfallenen, sondern ist auch Organisator: Er sorgt für Pflege und gibt Geld dafür. Beides zusammen kann heute kein Einzelner mehr leisten. Viele Professionelle arbeiten im Behandlungsprozess zusammen, was gute Organisation erfordert.