Examining multi-functionality for crop yield and ecosystem services in five systems of agroecological intensification

Agroecological intensification (AEI) integrates ecological principles and biodiversity management into farming systems with the aims of increasing farm productivity, reducing dependency on external inputs, and sustaining or enhancing ecosystem services. This review develops an analytic framework to characterize the fulfilment of these objectives by documenting the co-occurrence of positive, neutral, and negative outcomes for crop yield and nine regulating ecosystem services. We provide an illustrative examination of the framework, evaluating evidence for yield and ecosystem service outcomes across five AEI systems: conservation agriculture, holistic grazing management, organic agriculture, precision agriculture, and system of rice intensification (SRI). We reviewed 104 studies containing 245 individual comparisons between AEI and contrasting farming systems. In three of the five AEI systems, conservation agriculture, precision agriculture, and SRI, more than half of reviewed comparisons reported ‘win-win’ outcomes, enhancement of both yield and ecosystem services, or ‘win-neutral’ outcomes relative to contrasting farming systems. The review presents substantial evidence that the five AEI systems can contribute to multi-functional agriculture by increasing ecosystem service provision, or reducing negative externalities associated with agriculture, while maintaining or increasing yields. A framework such as the one presented here can help guide decision-makers considering how best to implement multi-functional agriculture so that both crop yield and ecosystem service delivery can be maintained or increased.     

Constitutional design and economic performance

This paper is motivated by the belief that some cultural traits favor economic performance more than others. One trait examined is the ease with which individuals in a community drift away from the spirit of the law for their own benefit; this, it is argued, generates verbose legislation and high-transaction-cost institutions with deleterious effects on economic performance. An empirical comparison between the number of articles in a country's constitution, as a proxy for length and lack of simplicity, and economic performance as measured by GDP per capita finds that no country with a high GDP per capita has a long constitution or, restated, that long constitutions are invariably associated with low levels of GDP per capita.     

Asymptotic and Bootstrap techniques for testing the expected value of a fuzzy random variable

In this paper we will consider hypothesis-tests for the (fuzzy-valued) mean value of a fuzzy random variable in a population. For this purpose, we will make use of a generalized metric for fuzzy numbers, and we will develop an approach for normal fuzzy random variables, and two different approaches for the case of fuzzy random variables taking on a finite number of different values. A real-life example illustrates the use of the last two approaches. Finally, a comparison between the introduced techniques is developed by means of simulation studies leading to close inferential conclusions.Acknowledgements.The research in this paper has been partially supported by MCYT Grants BFM2002-01057 and BFM2001-3494. Their financial support is gratefully acknowledged. The authors are sincerely grateful to their colleague Gil González-Rodríguez for all his comments and suggestions in connection with this paper; his scientific support has been very valuable. The authors want also thank the referees of the first version of the paper because of their useful hints to improve it.     

Least squares fitting of an affine function and strength of association for interval-valued data

The ultimate goal of this paper is to determine a measure of the degree of dependence between two interval-valued random sets, when the dependence is intended in the sense of an affine function relating these random elements. For this purpose, a general study on the least squares fitting of an affine function for interval-valued data is first carried out, where the least squares method we will present considers that squared residuals are based on a generalized metric on the space of nonempty compact intervals, and output and input random mechanisms are modelled by means of convex compact random sets. For the general case of nondegenerate convex compact random sets, solutions are presented in an algorithmic way, and the few cases leading to nonunique solutions are characterized. On the basis of this regression study we later introduce and analyze a well-defined determination coefficient of two interval-valued random sets, which will allow us to quantify the strength of association between them, and an algorithm for the computation of the coefficient has been also designed. Finally, a real-life example illustrates the study developed in the paper.  The research in this paper has been partially supported by DGESIC Grants DGE-99-PB98-1534 and DGE-98-PB97-1282 of the Spanish MEC. Their financial support is gratefully acknowledged. Acknowledgements. The authors are deeply grateful to Professor Wolfgang N?ther from the University of Freiberg and their colleagues Professors Norberto Corral, Miguel López-Dı′az and Ignacio MartVnez for their valuable comments and suggestions in connection with this paper. The real-life data which illustrate the study in this paper have been supplied by Aurora Fonseca, Head of the Servicio de Nefrologı′a, and Miguel de Zárraga, General Medical Manager, from the Hospital Valle del Nalón de Langreo in Asturias; we want to thank them sincerely for their collaboration and support.     

Green technology co-patenting networks: international dynamics

The present study examined how the multi-country green technology co-patenting network structure evolved from 1997 to 2016. For that purpose, we used Social Network Analysis tools, which allowed us to assess the network structure from a visual and quantitative perspective. The results indicate that the network expanded as the number of participating countries and ties increased. In all periods, the network grew significantly centralized around a small group of countries, in which the U.S., Great Britain, Germany, France, and Canada had paramount weight. Emerging countries like India and China also stood out due to their growth over time, as they eventually managed to gain central positions in the network. Other developing countries remained marginal, such as Brazil.