Minimal Hellinger martingale measures of order <Emphasis Type="Italic">q</Emphasis>

This paper proposes an extension of the minimal Hellinger martingale measure (MHM hereafter) concept to any order q≠1 and to the general semimartingale framework. This extension allows us to provide a unified formulation for many optimal martingale measures, including the minimal martingale measure of Föllmer and Schweizer (here q=2). Under some mild conditions of integrability and the absence of arbitrage, we show the existence of the MHM measure of order q and describe it explicitly in terms of pointwise equations in ? ^d . Applications to the maximization of expected power utility at stopping times are given. We prove that, for an agent to be indifferent with respect to the liquidation time of her assets (which is the market’s exit time, supposed to be a stopping time, not any general random time), she is forced to consider a habit formation utility function instead of the original utility, or equivalently she is forced to consider a time-separable preference with a stochastic discount factor.     

Machine learning for pricing American options in high-dimensional Markovian and non-Markovian models

In this paper we propose two efficient techniques which allow one to compute the price of American basket options. In particular, we consider a basket of assets that follow a multi-dimensional Black–Scholes dynamics. The proposed techniques, called GPR Tree (GRP-Tree) and GPR Exact Integration (GPR-EI), are both based on Machine Learning, exploited together with binomial trees or with a closed form formula for integration. Moreover, these two methods solve the backward dynamic programing problem considering a Bermudan approximation of the American option. On the exercise dates, the value of the option is first computed as the maximum between the exercise value and the continuation value and then approximated by means of Gaussian Process Regression. The two methods mainly differ in the approach used to compute the continuation value: a single step of the binomial tree or integration according to the probability density of the process. Numerical results show that these two methods are accurate and reliable in handling American options on very large baskets of assets. Moreover we also consider the rough Bergomi model, which provides stochastic volatility with memory. Despite that this model is only bidimensional, the whole history of the process impacts on the price, and how to handle all this information is not obvious at all. To this aim, we present how to adapt the GPR-Tree and GPR-EI methods and we focus on pricing American options in this non-Markovian framework.     

Confronting sustainable development in two rural heritage valorization models

Many rural areas have reinvented their territorial development through tourism, turning to vernacular heritage to ensure their future. Various models of heritage preservation and valorization are adopted where small-scale agriculture is no longer viable. Among them, ecomuseums and place-based labelization schemes transform rural heritage into an economic resource while remaining grounded in cultural and architectural preservation and identity transmission to future generations. Both face criticisms, including being decried as fostering the museumification and mythification of the rural, effectively holding back rural areas in an imagined and romanticized past rather than providing a vision for a sustainable future. The Association of the Most Beautiful Villages of France and the Ecomusée d'Alsace illustrate the debate. This investigation analyzes how these two initiatives challenge critics. It unveils their respective understandings of the future of rurality and their approach to promoting sustainable communities through tourism. By highlighting responses to tensions between valorizing the past and forward development in the countryside, findings reveal paradigm shifts from traditional habitat preservation to future-oriented architectural pedagogy in one case, while operational exigencies and normative quality principles mitigate opportunities in the other.     

A Comment on Weak Disposability in Nonparametric Production Analysis

In his 2005 paper in this journal, Kuosmanen argues that Shephard's specification of weak disposability in activity analysis (DEA) models is not correct. We show that Shephard's specification does satisfy weak disposability and is the "smallest" technology to do so.     

The Impact of an EU–US Transatlantic Trade and Investment Partnership Agreement on Biofuel and Feedstock Markets

We assess the impact of a potential TTIP bilateral free trade agreement on the EU and US bio‐economies (feedstock, biofuels, by‐products, and related competing crops) and major trade partners in these markets. The analysis develops a multi‐market model that incorporates bilateral trade flows (US to EU, EU to US, and similarly with third countries) and is calibrated to the OECD‐FAO baseline for 2013–2022 to account for recent policy decisions. The major policy reforms from a TTIP involve tariff and TRQ liberalisation and their direct contractionary impact on US sugar supply, EU biofuel production, and indirect negative effect on US high fructose corn syrup (HFCS) production. EU sugar and isoglucose production expand along with US ethanol and biodiesel and oilseed crushing. EU sugar would flow to the US, US biofuels and vegetable oil to the EU. We further quantify non‐tariff measures (NTM) affecting these trade flows between the EU and the US. EU oilseed production contracts, and EU crushing expands with improving crushing margins following reduced NTM frictions. Our analysis reveals limited net welfare gains with most net benefits reaped by Brazil and not the two trading partners of the TTIP.     

Christian Ethics and Spirituality in Leading Business Organizations: Editorial Introduction

Christian ethics applied to economics and business has a long tradition. This dates back at least to the thirteenth century, with noteworthy developments in the four following centuries and again in the last century. Christian faith and reason intertwine to bring about principles, criteria, and guidelines for action and a set of virtues with relevance for economic activity. Christian spirituality, with 2000 years of history, has been embedded in Christianity from its beginning, but the application to modern business activity is relatively recent. This article introduces a special issue which, we hope, will make its own small contribution to the developments of both Christian ethics and spirituality in the leading business organizations. After a short historical overview and a consideration of the current situation of Christian ethics and spirituality in business, we introduce the papers selected for this issue.     

Ethics in Finance and Accounting: Editorial Introduction

In light of the recent crisis and its aftershocks, it becomes crucial to reflect on the relationship between finance and accounting and on how to integrate ethics and efficiency, as well as on how to motivate and empower practitioners in the world of finance to commit to justice, fairness and enhanced understanding, and to improving their personal integrity. This article, written as an editorial introduction to a special issue includes works related to control measurement and ethical behavior, misbehaviors in finances and accounting, professionalism in accounting, ethical investing and corporate reporting. We conclude by suggesting further research for a better integration of technical aspects of accounting and finances into business activity—human activity actually—and an for understanding of ethics not limited to rules, but as a mutual and interdependent system of values (human goods), virtues and principles.     

Reflections on the Euro Area Fiscal Stance

Avoiding the mistakes of the past, when the good times were not used to build buffers, will be crucial to avoid countries again being forced to engage in a pro-cyclical fiscal tightening in the next downturn.