MINIMAL ENTROPY–HELLINGER MARTINGALE MEASURE IN INCOMPLETE MARKETS

This paper defines an optimization criterion for the set of all martingale measures for an incomplete market model when the discounted price process is bounded and quasi-left continuous. This criterion is based on the entropy–Hellinger process for a nonnegative Doléans–Dade exponential local martingale. We develop properties of this process and establish its relationship to the relative entropy "distance." We prove that the martingale measure, minimizing this entropy–Hellinger process, is unique. Furthermore, it exists and is explicitly determined under some mild conditions of integrability and no arbitrage. Different characterizations for this extremal risk-neutral measure as well as immediate application to the exponential hedging are given. If the discounted price process is continuous, the minimal entropy–Hellinger martingale measure simply is the minimal martingale measure of Föllmer and Schweizer. Finally, the relationship between the minimal entropy–Hellinger martingale measure (MHM) and the minimal entropy martingale measure (MEM) is provided. We also give an example showing that in contrast to the MHM measure, the MEM measure is not robust with respect to stopping.     

An Economic Evaluation of Model Risk in Long‐term Asset Allocations

Following the recent crisis and the revealed weakness of risk management practices, regulators of developed markets have recommended that financial institutions assess model risk. Standard risk measures, such as the value‐at‐risk (VaR), emerged during the 1990s as the industry standard for risk management and become today a key tool for asset allocation. This paper illustrates and estimates model risk, and focuses on the evaluation of its impact on optimal portfolios at various time horizons. Based on a long sample of US data, the paper finds a non‐linear relation between VaR model errors and the horizon that impacts optimal asset allocations.     

Sensitive products in the Doha negotiations: The case of European and Japanese market access

Given the highly concentrated distribution of agricultural protection, allowing in the negotiations too many exceptions through sensitive products puts at risk the objectives of World Trade Organization. This issue is difficult to analyze with the commonly used applied trade models, because they represent trade flows at an aggregate level, while sensitive products are picked at the product level and their protection, under the form of tariff-rate quotas, is contingent on the level of imports. This paper assesses the effect of these exceptions, based on the case of agricultural trade protection in Europe and Japan, two countries where tariff dismantling in the agricultural sector is a particularly sensitive issue. Since agricultural border protection is heterogeneous, we avoid aggregation bias by extending a multi-country computable general equilibrium model to the product level. This allows us to represent trade policies explicitly and to account for their interdependencies. The results suggest that consideration of sensitive products strongly limits the potential gains from a possible agriculture agreement at Doha. Moreover, there is no aggregate trade-off between decreasing tariffs and increasing/opening quotas. To achieve “substantial” market access improvements in the agricultural sector, the objective should be most favored nation tariff reduction.     

The cyclical impact of EU cohesion policy in fast growing EU countries

Most of the newly acceded central and east European EU countries are among the main beneficiaries of EU Cohesion Policy. The main objective of this policy is to improve the long-term growth and employment prospects of the supported regions, and thereby to support convergence towards higher levels of per capita income. In the short run, however, EU Cohesion Policy may at times amplify macroeconomic challenges for supported countries. In periods of a downturn of the economy it can have a stabilising impact. During periods of unsustainably fast economic growth, however, its short-term demand effects may contribute to internal and/or external macroeconomic imbalances. Economic policymakers should thus ensure that EU Cohesion Policy enhances long-term productivity, while avoiding, in times of overheating, an increased risk of unsustainable developments as a result of the additional demand stimulus from EU Cohesion Policy. The opinions expressed in this article are those of the authors and do not necessarily reflect those of the European Central Bank. The authors are grateful to Martin Bijsterbosch, Gesa Miehe-Nordmeyer, Ad van Riet, Philipp Rother and Desom Weller for their helpful comments.     

A re-examination of the technological catching-up hypothesis across OECD industries

This study re-examines the catching-up hypothesis at the industry level across the main OECD countries, using panel data econometric models involving technological gap indicators calculated with a nonparametric distance function suggested by Färe et al. [Färe, R.S., Grosskopf, M.N., Norris, M., Xhang, Z., 1994. Productivity growth, technical progress, and efficiency change in industrialized countries. American Economic Review 84, 66–83]. The results show that there is statistical evidence of a catching-up process at the industry level. Moreover, both tradables and nontradables sectors exhibit catching-up effects and technology adoption from abroad. This result complements the findings by Bernard and Jones [Bernard, A.B., Jones, C.I., 1996a. Comparing apples to oranges: productivity convergence and measurement across industries and countries. American Economic Review 86(5), 1216–1238., Bernard, A.B., Jones, C.I., 1996b. Productivity across industries and countries: Time series theory and evidence. Review Of Economics and Statistics 78, 135–146], Gouyette and Perelman [Gouyette, C., Perelman, S., 1997. Productivity convergence in OECD services industries. Structural Change and Economic Dynamics 8, 279–295] and Hansson and Henrekson [Hansson, P., Henrekson, M., 1997. Catching up, social capability, government size and economic growth, in V. Bergström, eds, Government and Growth, Oxford: Clarendon Press, 61–126] that there is no (or even a slow) catching-up effect in the manufacturing sector. Moreover, social capability indicators evaluated for each country show that “Non-European” and “Central European” tradables sectors have a rather similar degree of inefficiency while “North European” countries are less efficient for both tradables and non-tradables. Lastly, both the cross country and the cross sectors dispersions of inefficiency levels are smaller for tradables sectors than for non-tradables.     

Exogeneity in Vector Error Correction Models with Purely Exogenous Long-Run Paths

Existing exogeneity conditions of literature are only sufficient and imply 'overly strong' constraints on long-run parameters. This paper presents some new results on exogeneity in vector error correction models. A key concept of the analysis is the 'purely exogenous long-run path', i.e. a cointegrating vector only including 'exogenous' variables. Extending earlier results of Johansen, S. (1992). 'Cointegration in partial systems and the efficiency of single-equation analysis', Journal of Econometrics , Vol. 52, pp. 389–402 and of Toda and Phillips (1991) . Vector Autoregressions and Causality , Cowles Foundation Discussion Paper, No. 977 among others, we propose a framework based on two canonical representations of the long-run matrix, which can constitute a suitable basis to formulate a necessary and sufficient condition for non-causality as well as a condition for strong exogeneity. An interesting property is that the statistics involved in the sequential procedures for testing these conditions are distributed as χ ² variables and can, therefore, easily be calculated with the usual statistical computer packages, which makes our approach fully operational, empirically. Finally, the power and size distortions of the sequential test procedures are analysed using Monte Carlo experiments.     

Generalized vs. specific locus of control expectancies of chief executive officers

Hodgkinson (1992) recently advocated in this journal that measures of generalized control expectancies, such as the well known Rotter I-E scale (Rotter, 1966), are not suited to study the relationship between the locus of control beliefs of Chief Executive Officers (CEOs) on the one hand and strategic, structural and performance variables on the other hand. According to Hodgkinson (1992) a more specific scale, measuring strategic control expectancies, should be used in future research. We argue and empirically illustrate that such a methodology will not lead to interesting research results in the ‘strategic leadership’ domain. More specifically, measures of firm-specific control expectancies are likely to be influenced by the CEO's perception of the situational context of the firm and are therefore not indicative of fundamental personality differences between CEOs. Consequently, such measures cannot give an answer to the basic research question whether and why the personality of CEOs plays an important role in explaining organizational behavior and performance.     

THE MEASUREMENT OF POVERTY WITH GEOGRAPHICAL AND INTERTEMPORAL PRICE DISPERSION: EVIDENCE FROM RWANDA

It is not known to what extent welfare measures result from seasonal and geographical price differences rather than from differences in living standards across households. Using data from Rwanda in 1983, we show that the change in mean living standard indicators caused by local and seasonal price deflation is moderately significant at every quarter. By contrast, the differences in poverty measures caused by this deflation can be considerable, for chronic as well as transient or seasonal poverty indicators. Thus, poverty monitoring and anti-poverty targeting can be badly affected by inaccurate deflation of living standard data. Moreover, when measuring seasonal poverty, the deflation based on regional prices instead of local prices only partially corrects for spatial price dispersion. Using annual local prices instead of quarterly local prices only yields a partial deflation, which distorts the measure of poverty fluctuations across seasons and biases estimates of annual and chronic poverty.     

On the Construction of the European Economic Sentiment Indicator*

Economic sentiment surveys are carried out by all European Union member states and are often seen as early indicators for future economic developments. Based on these surveys, the European Commission constructs an aggregate European Economic Sentiment Indicator (ESI). This paper compares the ESI with more sophisticated aggregation schemes based on statistical methods: dynamic factor analysis and partial least squares. The indicator based on partial least squares clearly outperforms the other two indicators in terms of comovement with economic activity. In terms of forecast ability, the ESI, constructed in a rather ad hoc way, can compete with the other indicators.