The pillowcase distribution and near-involutions

In the context of the Eskin-Okounkov approach to the calculation of the volumes of the different strata of the moduli space of quadratic differentials, the important ingredients are the pillowcase weight probability distribution on the space of Young diagrams, and the asymptotic study of characters of permutations that near-involutions. In this paper we present various new results for these objects. Our results give light to unforeseen difficulties in the general solution to the problem, and they simplify some of the previous proofs.Comment: This paper elaborates on some of the results of the author's PhD thesis (arXiv:1209.4333). This is the published version, http://ejp.ejpecp.org/article/view/362

Isovector properties of the Gogny interaction

We analyse the properties of the Gogny interaction in homogeneous matter, with special emphasis on the isovector sector. We provide analytical expressions for both the single-particle and the bulk properties of symmetric and asymmetric nuclear matter. We perform an extensive analysis of these properties using 11 parametrizations extracted from the literature. We find that most Gogny interactions have low values for the slope of the symmetry energy, outside the range of empirically extracted values. As a test of extreme isospin dependence, we also study the mass-radius relations implied by the different Gogny equations of state. Our results call for a more careful fitting procedure of the isovector properties of Gogny functionals.Comment: 23 pages, 14 figures, 1 table. Final published version, typos correcte

Poor household participation in payments for environmental services in Nicaragua and Colombia

We evaluate the extent to which poor households are able to participate in Payments for Environmental Services (PES) scheme using data from a PES scheme implemented at two sites in Latin America. This allows us to compare environmental and livelihood impacts of PES across regions with different agronomic and socio-economic characteristics. In particular, one of our sites is composed almost entirely of poor or extremely poor households, while the other has households ranging from extremely poor to very well off. The results show that poorer households are in fact able to participate—indeed, by some measures they participated to a greater extent than better-off households. Moreover, their participation was not limited to the simpler, least expensive options. Extremely poor households had a somewhat greater difficulty in participating, but even in their case the difference is solely a relative one. Transaction costs may be greater obstacles to the participation of poorer households than household-specific constraints.Payments for environmental services, PES, poverty, silvopastoral

N_c and m_pi dependence of rho and sigma mesons from unitarized Chiral Perturbation Theory

We review our work on the rho and sigma resonances derived from the Inverse Amplitude Method. In particular, we study the leading 1/N_c behavior of the resonances masses and widths and their evolution with changing m_pi. The 1/N_c expansion gives a clear definition of quark-antiquark states, which is neatly satisfied by the rho but not by the sigma, showing that its dominant component is not quark-antiquark. The m_pi dependence of the resonance properties is relevant to connect with lattice studies. We show that our predictions compare well with some lattice results and we find that the rho-pi-pi coupling constant is m_pi independent, in contrast with the sigma-pi-pi coupling, that shows a strong m_pi dependence.Comment: To appear in the Proceedings of the Chiral10 Workshop, June 21-24 2010. Valencia, Spai

Farm size and nonparametric efficiency measurements for coffee farms in Vietnam

We study the efficiency of smallholder coffee farms in Vietnam. Data from a 2004 survey of farms in two districts in Dak Lak Province are used in a two-step analysis. In the first step, technical and cost efficiency measures are calculated using DEA. In the second step, Tobit regressions are used to identify factors correlated with technical and cost inefficiency. Results indicate that small farms were less efficient than large farms. Inefficiencies observed on small farms appear to be related, in part, to the scale of investments in irrigation infrastructure.Farm Management,

U.S. Agriculture: Commercial and Large Producer Concentration and Implications for Agribusiness Segments

This study examines rate of concentration of farms and sales for aggregate farm production and crop and livestock activities during the 1982 to 2002 period. Data from the Census of Agriculture are used to calculate Theil's relative entropy measure as an indicator of concentration. Results indicate that Grain segments are lagging behind cotton, potato and hog segments in terms of concentration of total sales, while concentration in the dairy segment appears to be gaining steam. Agribusiness serving less concentrated industry segments should look to the more concentrated segments as leading indicators for effective marketing strategies as concentration increases.Concentration, Commodities, Entropy, Agribusiness,

U.S. Agriculture: Commercial and Large Producer Concentration and Implications for Agribusiness Segments

This study examines rate of concentration of farms and sales for aggregate farm production and crop and livestock activities during the 1982 to 2002 period. Data from the Census of Agriculture are used to calculate Theil's relative entropy measure as an indicator of concentration. Results indicate that Grain segments are lagging behind cotton, potato and hog segments in terms of concentration of total sales, while concentration in the dairy segment appears to be gaining steam. Agribusiness serving less concentrated industry segments should look to the more concentrated segments as leading indicators for effective marketing strategies as concentration increases.Concentration, Commodities, Entropy, Agribusiness,