Implications of nanotechnology growth in food and agriculture in OECD countries

This article provides an analysis of the implications of the growth of nanotechnology in the agriculture and food sector in OECD countries. Three main policy challenges are identified related to funding and investment, risk governance, and public acceptance. Each of these interconnected challenges underlines a number of ethical questions that need to be addressed. Several recommendations are laid out to move forward and adapt to these emerging policy issues.     

A Market Efficiency Comparison of Islamic and Non-Islamic Stock Indices

This article examines the martingale difference hypothesis (MDH) and the random walk hypothesis (RWH) for nine conventional and nine Islamic stock indices: Asia-Pacific, Canadian, Developed Country, Emerging, European, Global, Japanese, UK, and United States. It investigates whether Islamic stock indices are more, less, or as efficient as their conventional counterparts. We test four sub-periods of bullish and bearish stock markets, together with the financial meltdown and its recovery, over the period 1997–2012. We use the Escanciano and Lobato’s (2009) automatic portmanteau test (AQ) and Deo’s (2000) test for the MDH. We also apply the automatic variance ratio test (AVR) developed by Choi (1999) and Kim (2009) for the RWH. Over the period from 1997 to 2012, we find that three conventional indices (Europe, Japan, and UK) are efficient, but that none of the Islamic indices are efficient in these markets. During the recent financial crisis, our results indicate slightly more efficiency for the Islamic indices than their conventional counterparts. Our study finds that overall the conventional indices are more efficient than their Islamic counterparts. Nevertheless, during periods of general downturns the Islamic indices have shown the same level of efficiency as their counterparts. Furthermore, it appears that during the last two sub-periods under study, the Islamic indices have moved toward efficiency, displaying the same level of efficiency as their counterparts.     

Diversified minimum-variance portfolios

We build on a one parameter family of weighting schemes arising from \(L^2\)-constrained portfolio optimization problems. The parameter allows to fine tune the trade-off between the volatility and the diversification of the portfolio. We propose two criteria in order to determine two unique portfolios: the first criterion requires that no weights be negative while the second one imposes a target diversification which is median between full concentration and full diversification. Both portfolios are empirically compared to classical benchmarks. The first one behaves very much like other popular Long-Only weighting schemes while the second displays a more aggressive profile, while generating moderate turnover. We also discuss implementation issues, as well as estimation related problems.     

Entrepreneurs' financing choice between independent and bank-affiliated venture capital firms

This paper analyzes how the affiliation of a venture capital firm affects the deal terms for innovative entrepreneurial ventures. We develop a theory to explain the advantages of independent and bank-affiliated venture capital funds for entrepreneurs. We assume that independent venture capital firms provide better support quality while bank-affiliated firms are less financially constrained. The entrepreneur selects the optimal contract by trading-off these characteristics. The model allows several empirically testable predictions concerning the nature of projects financed by either type of venture capital firm. Entrepreneurs should seek capital from independent or affiliated venture capitalists contingent on the degree of sophistication of their project, their liquidation value, the importance of expected management support, and the remaining time to fundraising.     

Fiscal sustainability in the presence of systemic banks: the case of EU countries

We provide a first attempt to include an off-balance sheet, implicit insurance to SIFIs into a consistent assessment of fiscal sustainability, for 27 countries of the European Union. We first calculate tax gaps à la Blanchard (OECD Economics Department Working Papers, No 79, 1990) and Blanchard et al. (Revue économique de l’OCDE, 1990). We then introduce two alternative measures of implicit off-balance sheet liabilities related to the risk of a systemic bank crisis. The first one relies on microeconomic data at the bank level. The second one is based on econometric estimations of the probability and the cost of a systemic banking crisis. The former approach provides an upper evaluation of the fiscal cost of systemic banking crises, whereas the latter one provides a lower one. Hence, we believe that the combined use of these two methodologies helps to gauge the range of fiscal risk.     

Stochastic modelling of herd behaviour indices

This paper proposes different diffusion processes to model herd behaviour indices such as the Herd Behaviour Index (HIX). These models arise by combining popular mean-reverting processes with simple algebraic functions mapping the definition domain of the underlying mean-reverting process to the unit interval. The so obtained Itô processes preserve, to some extent, the mean-reverting trend of the underlying process while satisfying the fundamental properties of the so-called herd behaviour indices. In a numerical study, we calibrate the different model settings to time series data for a period spanning from January 2000 until October 2009 and investigate their ability to predict the future behaviour of herd behaviour indices.     

A preliminary comparison of the retail level effects of genetically modified food labelling policies in Canada and France

Most developed countries have adopted labelling policies for genetically modified (GM) food. In April 2004, Canada implemented a voluntary labelling policy for GM and non-GM food, while France adopted the European Union’s new extended mandatory labelling of GM food. I present the result of a qualitative survey of GM and non-GM food labels in supermarkets in Canada and France, five months after the introduction of the new policies. I find that there are almost no GM labelled products in France and non-GM labelled products in Canada. Each policy tends to crowd out the targeted label attribute. However, Canadian consumers can choose between GM and non-GM organic products, whereas there are only non-GM products in French supermarkets. Recent political developments in Quebec suggest that the labelling landscape may change in Canada, either with an increase in the number of non-GM products at the retail level or a transition towards a mandatory labelling policy like in France.     

Adopting telework: The causal impact of working from home on subjective well-being

We study the impact of work from home (WFH) on subjective well-being during the Covid period, where self-selection of individuals into telework is ruled out, at least part of the time, by stay-at-home orders. We use a difference-in-differences approach with individual fixed effects and identify the specific impact of switching to telecommuting, separately from any other confounding factor. In particular, our identification strategy avoids the influence of interpersonal heterogeneity by exploiting the multiple entries into WFH, by the same individuals, at different times. On average over the period, switching to WFH, especially full-time, worsens mental health. We also find a positive but imprecisely measured impact of part-time WFH on life satisfaction. However, this hides a dynamic evolution, whereby the initial deterioration gives place to an adaptation process after a couple of months. We also uncover a particularly pronounced fall in subjective well-being of women with children, especially in the first months; this could be associated with home-schooling.     

Inference in models with adaptive learning

Identification of structural parameters in models with adaptive learning can be weak, causing standard inference procedures to become unreliable. Learning also induces persistent dynamics, and this makes the distribution of estimators and test statistics non-standard. Valid inference can be conducted using the Anderson-Rubin statistic with appropriate choice of instruments. Application of this method to a typical new Keynesian sticky-price model with perpetual learning demonstrates its usefulness in practice.     

Platform Pricing Structure and Moral Hazard

We study pricing by a two‐sided platform when it faces moral hazard on the sellers' side. In doing so, we introduce an equilibrium notion of platform reputation in an infinite horizon model. We find that with transaction fees only, the platform cannot eliminate the loss of reputation induced by moral hazard. If registration fees can be levied, moral hazard can be overcome. The registration fee determines the participation threshold of sellers and extracts them, whereas (lower) transaction fees provide incentives for good behavior. This provides a motivation for platforms to use registration fees in addition to transaction fees.