Endogenous Time Preference and Strategic Growth

This paper presents a strategic growth model that analyzes the impact of Endogenous preferences on equilibrium dynamics by employing the tools provided by lattice theory and supermodular games. Supermodular game structure of the model let us provide monotonicity results on the greatest and the least equilibrium without making any assumptions regarding the curvature of the production function. We also sharpen these results by showing the differentiability of the value function and the uniqueness of the best response correspondence almost everywhere. We show that, unlike globally monotone capital sequences obtained under corresponding optimal growth models, a non-monotonic capital sequence can be obtained. We conclude that the rich can help the poor avoid poverty trap whereas even under convex technology, the poor may theoretically push the rich to her lower steady state.Lattice programming, Endogenous time preference

Using numerical plant models and phenotypic correlation space to design achievable ideotypes

Numerical plant models can predict the outcome of plant traits modifications resulting from genetic variations, on plant performance, by simulating physiological processes and their interaction with the environment. Optimization methods complement those models to design ideotypes, i.e. ideal values of a set of plant traits resulting in optimal adaptation for given combinations of environment and management, mainly through the maximization of a performance criteria (e.g. yield, light interception). As use of simulation models gains momentum in plant breeding, numerical experiments must be carefully engineered to provide accurate and attainable results, rooting them in biological reality. Here, we propose a multi-objective optimization formulation that includes a metric of performance, returned by the numerical model, and a metric of feasibility, accounting for correlations between traits based on field observations. We applied this approach to two contrasting models: a process-based crop model of sunflower and a functional-structural plant model of apple trees. In both cases, the method successfully characterized key plant traits and identified a continuum of optimal solutions, ranging from the most feasible to the most efficient. The present study thus provides successful proof of concept for this enhanced modeling approach, which identified paths for desirable trait modification, including direction and intensity.Comment: 25 pages, 5 figures, 2017, Plant, Cell and Environmen

Hydrodynamic capabilities of an SPH code incorporating an artificial conductivity term with a gravity-based signal velocity

This paper investigates the hydrodynamic performances of an SPH code incorporating an artificial heat conductivity term in which the adopted signal velocity is applicable when gravity is present. In accordance with previous findings it is shown that the performances of SPH to describe the development of Kelvin-Helmholtz instabilities depend strongly on the consistency of the initial condition set-up and on the leading error in the momentum equation due to incomplete kernel sampling. An error and stability analysis shows that the quartic B-spline kernel (M_5) possesses very good stability properties and we propose its use with a large neighbor number, between ~50 (2D) to ~ 100 (3D), to improve convergence in simulation results without being affected by the so-called clumping instability. SPH simulations of the blob test show that in the regime of strong supersonic flows an appropriate limiting condition, which depends on the Prandtl number, must be imposed on the artificial conductivity SPH coefficients in order to avoid an unphysical amount of heat diffusion. Results from hydrodynamic simulations that include self-gravity show profiles of hydrodynamic variables that are in much better agreement with those produced using mesh-based codes. In particular, the final levels of core entropies in cosmological simulations of galaxy clusters are consistent with those found using AMR codes. Finally, results of the Rayleigh-Taylor instability test demonstrate that in the regime of very subsonic flows the code has still several difficulties in the treatment of hydrodynamic instabilities. These problems being intrinsically due to the way in which in standard SPH gradients are calculated and not to the implementation of the artificial conductivity term.Comment: 26 pages, 15 figures, accepted for publication in A&

The Economics of Policies and Programs Affecting the Employment of People with Disabilities

Over the last several decades, there has been a movement toward the inclusion of people with disabilities in mainstream social institutions. The 1990 Americans with Disabilities Act (ADA), which supports the full participation of people with disabilities in society and mainstream institutions, illustrates the shift in attitudes toward people with disabilities. Rather than being perceived as having a social or medical problem, individuals with disabilities are increasingly viewed as people with challenges that can be solved if appropriate policies and supports are available for addressing them

Unmentionable: Socio-Structural Discrimination of Incontinence; Engendering Dignity by Design

Although present in medical and historical texts for millennia, urinary incontinence remains a somewhat taboo topic, with both affected individuals and remedies for the condition--such as adult diapers--subject to ridicule, embarrassment, status loss, discrimination, and even exile. Reinforcing this discriminatory behavior, the adult diaper--a spur from the baby diaper invention--tracks a parallel path to incontinence. With diapers and adult incontinence rooted in a misunderstood cross-pollination with infant incontinence, individuals must struggle against known stereotypes and stigmas liable to label them as incompetent, impotent, or unclean. The stigma of incontinence is thus aligned with the diaper, reinforcing social ignorance and discriminating structural environments. Establishments of structural discrimination, such as medical providers and architectural policy, are instrumental in perpetuating the stigma of urinary incontinence through their unimpeachable status and concomitant power. Product, social structure, power systems and architecture are inevitably linked in the case of systemic disenfranchisement. In this study, the adult diaper is seen as one key to crippling such mechanisms and inspire new direction and greater dignity within incontinent populations. Synthesizing qualitative and quantitative research on product history, product function, market trends, material trends, user needs, and product testing, a case is made for a reusable incontinence garment...at first hybridized with disposable technology and later envisioned to connect with emerging trends in wearable technology, urine collection and agricultural systems. Enabling such synapses between seemingly disparate parts, argues that dignity may be engendered in populations upon establishing multidimensional strategies within product research and design, with the intent of transcending personal and cultural biases

Why exporters can be financially constrained in a recently liberalised economy? A puzzle based on Argentinean firms during the 1990s

Trade-related characteristics have only been recently started to be included in empirical studies analysing the determinants of the financial constraints faced by firms. A result broadly shared by these studies is that exporting firms tend to be those less financially constrained. In this paper we test this result using panel data built up from quarterly balance sheet information for 74 Argentinean big firms covering the years of the currency board regime (1992-2001). We estimate an investment equation splitting up the sample between exporters and non-exporters. Using three alternative econometric models (random effects, fixed effects and instrumental variables) we find that, contrary to what is commonly stressed in the literature, exporting firms are the ones facing larger financial constraints on investment. We propose an explanation for this original result based on the currency appreciation that follows financial liberalisation processes in emerging countries, particularly in Argentina, which triggers a profit squeeze phenomenon for exportable firms, reducing their investment capacity.financial constraint,investment,foreign trade,Argentine