Managing Irrigation Risk with Inflow-Based Derivatives: The Case of Rio Mayo Irrigation District in Sonora, Mexico

Uncertain reservoir inflows represent a major source of risk for irrigated agriculture. A derivative instrument that uses reservoir inflows as the underlying variable is designed and tested with a recursive stochastic simulation of the Rio Mayo irrigations system. The results indicate that the instrument effectively protects against downside risk.Risk and Uncertainty,

The Economic Value of A Passport: A Model of Citizenship and the Social Dividend in a Global Economy -

In a world of fully mobile capital and highly immobile labour, citizenship is effectively an entitlement to the 'dividend' arising from the social infrastructure accumulated in a particular country of birth. The paper opens with the reasons why the passport (ie citizenship) can in consequence be considered as an economic asset with a value that can in principle be determined analytically. A simple endogenous growth model is set up which defines the level and growth of per capita income in a world economy where capital is fully mobile and labour is fully immobile, and where governments set a rate of taxation such as to achieve the optimal balance between the stocks of private capital and social infrastructure. The 'passport value' is then defined as the difference between national income net of capital charges, wage costs and taxes when divided equally among the population; and is shown to depend on per capita income, the rate of growth and the parameters of the production function. A preliminary estimate of the main variables in the model, and the scale of expenditure on social infrastructure, for a wide range of countries suggests what the order of magnitude of the 'value of a passport' might be. A brief section on the wider implications of the findings concludes.

An Empirical Evaluation of Irrigation Insurance for Agricultural Systems in the Mexican Northwest

Prototype inflow-based derivative contracts are designed to hedge irrigation risk in the Rio Mayo Valley of Sonora, Mexico. The results indicate that an 18-month contract is feasible given the specific characteristics of the region selected for the study.Risk and Uncertainty,

MAMA: An Algebraic Map for the Secular Dynamics of Planetesimals in Tight Binary Systems

We present an algebraic map (MAMA) for the dynamical and collisional evolution of a planetesimal swarm orbiting the main star of a tight binary system (TBS). The orbital evolution of each planetesimal is dictated by the secular perturbations of the secondary star and gas drag due to interactions with a protoplanetary disk. The gas disk is assumed eccentric with a constant precession rate. Gravitational interactions between the planetesimals are ignored. All bodies are assumed coplanar. A comparison with full N-body simulations shows that the map is of the order of 100 times faster, while preserving all the main characteristics of the full system. In a second part of the work, we apply MAMA to the \gamma-Cephei, searching for friendly scenarios that may explain the formation of the giant planet detected in this system. For low-mass protoplanetary disks, we find that a low-eccentricity static disk aligned with the binary yields impact velocities between planetesimals below the disruption threshold. All other scenarios appear hostile to planetary formation

Modeling Exit and Entry of Farmers in a Crop Insurance Program

This paper examines the factors influencing farmer participation in crop insurance schemes, but unlike previous studies that focus on total demand, participation is disaggregated into entrants and those exiting. Modeling entry and exit decisions separately illustrates that the effect of a given variable is often muted by aggregation. In addition, the approach in this paper distinguishes between price and yield variables rather than total returns and is consequently able to demonstrate that price variables are particularly important for farmers considering enrolling in crop insurance, while yield variables and other risk management opportunities are more important for farmers who have been in the program but are deciding to exit. The result suggests that moral hazard is reduced significantly by calculating the coverage yield level for an individual producer on the basis of a moving average of past yields for that farmer. While yield and its variance are particularly influential in the participation decision for farmers currently enrolled, its significant impact on the insurance decision for all farmers highlights the importance of crop insurance as a potential adaptation strategy to weather events.crop insurance, entry and exit, panel data, Risk and Uncertainty,

Generalized commutation relations and Non linear momenta theories, a close relationship

A revision of generalized commutation relations is performed, besides a description of Non linear momenta realization included in some DSR theories. It is shown that these propositions are closely related, specially we focus on Magueijo Smolin momenta and Kempf et al. and L.N. Chang generalized commutators. Due to this, a new algebra arises with its own features that is also analyzed.Comment: accepted version in IJMP

Constitution, neoconstitucionalismo and loopholes (normative and axiological)

Indexación: Web of Science; ScieloResumen: El presente trabajo analiza el impacto de la Constitucionalización del Derecho, especialmente del denominado Neoconstitucionalismo, en el fenómeno de las lagunas normativas y axiológicas. Destaca que en el contexto descrito la relación entre la Constitución y los mencionados tipos de lagunas jurídicas es ambivalente. De una parte las Cartas Fundamentales disiparían las lagunas normativas, mientras que por otra contribuirían a la generación de lagunas axiológicas.Abstract: This paper analyzes the impact of the constitutionalization of the right, especially of the so-called Neoconstitucionalismo, in the phenomenon of the normative and axiological lagoons. Stresses that in the context described the relationship between the Constitution and the above-mentioned types of loopholes is ambivalent. The fundamental letters part they allay regulatory gaps, while on the other they would contribute to the generation of axiological lagoons. Key words: constitutionalism, Neoconstitucionalismo, legal gaps.http://ref.scielo.org/dyhkz

¿Neo?-constitucionalismo

El presente trabajo plantea la existencia de coincidencias entre las ideas más representativas del Neoconstitucionalismo con elementos desarrollados previamente por el denominado Movimiento del Derecho Libre.This paper discusses the existence of similarities between the most representative ideas Neoconstitutionalism with items previously developed by the so-called Freirechtsbewegung

About Neo-Constitutionalism. A Synthesis for Constitutionalists with a Legal Theoretician’s Spirit

El presente trabajo ensaya una síntesis de las principales tesisasociadas al neoconstitucionalismo en sus diversas formas. Analizasus orígenes conceptuales y sus postulados principales, ademásde destacar en su parte final los elementos inconclusos de esteconjunto de ideas.This article provides a synthesis of the main theses associated tothe several types of neo-constitutionalism. The article analyzes itsconceptual origin and its main hypotheses and finally outlines theuncompleted elements of these ideas