Utility maximization under a shortfall risk constraint

The article analyzes optimal portfolio choice of utility maximizing agents in a general continuous-time financial market model under a joint budget and downside risk constraint. The risk constraint is given in terms of a class of convex risk measures. We do not impose any specific assumptions on the price processes of the underlying assets. We analyze under which circumstances the risk constraint is binding. We provide a closed-form solution to the optimization problem in a general semimartingale framework. For a complete market, the wealth maximization problem is equivalent to a dynamic portfolio optimization problem.     

Sustainable humanitarian supply chain management – exploring new theory

Disaster response operations aim at helping as many victims as possible in the shortest time, with limited consideration of the socio-economic context. During the disaster rehabilitation phase, the perspective needs to broaden and comprehensively take into account the local environment. We propose a framework of sustainable humanitarian supply chain management (SCM) that facilitates such comprehensive performance. We conceptualise the framework by combining literature from the fields of sustainable and humanitarian SCM. We test the framework through an analytic induction process by means of multiple case studies of four relief organisations. Our framework suggests that supply chain design needs to be aligned not only to relief organisations’ enablers, but also to the population's long-term requirements as well as any socio-economic and governmental contingency factors. A good fit between these dimensions leads to sustainable performance. The framework provides an instrument for relief organisations to achieve sustainable performance in the disaster rehabilitation phase.     

Increasing the price variation in a repeated cross section

Insufficient price variation seriously hampers many applications of consumer demand models. This paper examines the empirical performance of a potential remedy for this problem that was suggested by [Lewbel, A., 1989. Identification and estimation of equivalence scales under weak separability. Review of Economic Studies 56, 311–316], the construction of individual specific price indices for bundles of goods. These individual specific price indices allow for a population with heterogeneity in preferences for goods within a given bundle of goods. We confine ourselves to heterogeneous Cobb Douglas within bundle preferences, while between bundles, we allow for several parametric and even general nonparametric specifications. In a variety of settings, we show that such prices produce superior empirical results than the ones obtained through the traditional practice of using aggregate price indices. Our empirical analysis is based on the British Family Expenditure Survey data, and uses several categories of food. Both in parametric as well as nonparametric models, we obtain higher precision of estimates for parameters or functions, as well as economically more plausible results.     

The α-beauty contest: Choosing numbers, thinking intervals

We present a model for the α-beauty contest that explains common patterns in experimental data of one-shot and iterative games. The approach is based on two basic assumptions. First, players iteratively update their recent guesses. Second, players estimate intervals rather than exact numbers to cope with incomplete knowledge of other players' rationality. Under these assumptions we extend the cognitive hierarchy model of Camerer et al. [Camerer, C., Ho, T., Chong, J., 2003b. A cognitive hierarchy model of one-shot games. Quart. J. Econ. 119, 861–898]. The extended model is estimated on experimental data from a newspaper experiment.     

Structural production layer decomposition: a new method to measure differences between MRIO databases for footprint assessments

Recent empirical assessments revealed that footprint indicators calculated with various multi-regional input–output (MRIO) databases deliver deviating results. In this paper, we propose a new method, called structural production layer decomposition (SPLD), which complements existing structural decomposition approaches. SPLD enables differentiating between effects stemming from specific parts in the technology matrix, e.g. trade blocks vs. domestic blocks, while still allowing to link the various effects to the total region footprint. Using the carbon footprint of the EU-28 in 2011 as an example, we analyse the differences between EXIOBASE, Eora, GTAP and WIOD. Identical environmental data are used across all MRIO databases. In all model comparisons, variations in domestic blocks have a more significant impact on the carbon footprint than variations in trade blocks. The results provide a wealth of information for MRIO developers and are relevant for policy makers designing climate policy measures targeted to specific stages along product supply chains.     

LEADERSHIP IN CLIMATE CHANGE MITIGATION: CONSEQUENCES AND INCENTIVES

Initiatives in favor of unilateral action on climate change are frequently challenged by concerns over free riding. Nevertheless, we observe an increasing number of unilateral efforts at different administrative levels and in different parts of the world. Previous academic literature described various individual mechanisms where emissions abroad may increase or decrease as a reaction to unilateral emission reductions. In this paper, we collect a comprehensive set of both positive and negative reactions and analyze them in stylized models. This allows us to identify the most important characteristics that determine the potential of a leader to boost mitigation efforts abroad. We find that this potential depends on (i) a strong ability to generate knowledge through leadership, (ii) a high degree of credibility in the international community, and (iii) a similar economic structure to the most important emitters. While most effects are difficult to quantify, this comprehensive assessment suggests that leakage effects resulting from unilateral mitigation may well be outweighed by positive reactions.     

The multiple filter test for change point detection in time series

A framework for the detection of change points in the expectation in sequences of random variables is presented. Specifically, we investigate time series with general distributional assumptions that may show an unknown number of change points in the expectation occurring on multiple time scales and that may also contain change points in other parameters. To that end we propose a multiple filter test (MFT) that tests the null hypothesis of constant expectation and, in case of rejection of the null hypothesis, an algorithm that estimates the change points.The MFT has three important benefits. First, it allows for general distributional assumptions in the underlying model, assuming piecewise sequences of i.i.d. random variables, where also relaxations with regard to identical distribution or independence are possible. Second, it uses a MOSUM type statistic and an asymptotic setting in which the MOSUM process converges weakly to a functional of a Brownian motion which is then used to simulate the rejection threshold of the statistical test. This approach enables a simultaneous application of multiple MOSUM processes which improves the detection of change points that occur on different time scales. Third, we also show that the method is practically robust against changes in other distributional parameters such as the variance or higher order moments which might occur with or even without a change in expectation. A function implementing the described test and change point estimation is available in the R package MFT.     

Non-uniformity of job-matching in a transition economy – A nonparametric analysis for the Czech Republic

This study explores the properties and development of the matching technology in the Czech Republic during the transition to a market economy. Nonparametric additive modelling allows us to assess flexible functional forms, which comprise for instance CES and trans-log specifications. This enables us to evaluate the matching process locally for each combination of unemployment and vacancies rather than being restricted to global coefficients. Special interest is devoted to analysis and economic determinants of regional variation in the returns to scale of the matching function. Non-linearities are found in the partial adjustment process of unemployment outflows, and a negative coefficient on vacancies in some years. Moreover, increasing returns to scale in job-matching are found locally. Returns to scale are found to be negatively correlated to the share in employment in services and to outmigration, positively correlated to the employment share in industry, the unemployment rate and various measures of active labour market policies.     

Unit root tests of the current account balance: implications for international capital mobility

The extent of international capital mobility is assessed in a time series context. The possibility that the current account balance of different 0ECD countries contains a unit root is explored. It is shown that if the ratio of the current account balance to GDP is found to be integrated of the order of one, the country is likely to be part of the world capital market. The results for the whole period 1950–1988 indicate that the current account balance of at least Germany, Japan and the United States contains a unit root. Considering the subperiods before and after 1972 it is shown that international capital mobility increased after the breakdown of the Bretton Woods System.     

Human Capital and Growth Cycles

This paper studies the dynamic interaction between human capital accumulation and economic growth. Capital market imperfections and an indivisibility in human capital investment prevent poor agents from accumulating skills, the acquisition of which positively affects technological progress. More productive technologies in turn require more sophisticated qualification and involve higher training costs. The equilibrium dynamics can be characterized by the joint evolution of productivity growth, the schooling costs, and the income distribution. Under our assumptions, individual incomes follow a non-linear Markov chain. This non-linearity generates endogenous fluctuations of schooling activities and the rate at which productivity improvements occur. We thank an anonymous referee for many helpful suggestions. Support from the German Research Foundation (DFG) under grant KA1519/2-2 is gratefully acknowledged.