Three Essays on Labor and Public Economics

This dissertation consists of three chapters in the area of applied microeconomics. Using a variety of quasi-experimental research designs, they study the labor market effects of a wage subsidy in a highly informal economy, the impact of a tax-breaks program on small formal firms\u27 entrance decision and the probability of survival, and the impact of exposure to neighborhood crime on school absenteeism, respectively. The first chapter studies the labor market effects of a wage subsidy introduced in Colombia\u27s First Job Act. It exploits changes in the labor earnings distribution to measure how the policy change affected net employment, the relative sizes of the formal and informal labor markets, and the subsidy\u27s excess burden. The results indicate the policy caused sizable shifts of workers across the formal and informal labor markets, but relatively little net employment growth. The policy\u27s marginal excess burden ranges from 0.1% to 4% of corporate income tax revenues, which the paper argues represent a lower bound for what the benefits of moving workers across sectors should be, for the policy to be welfare enhancing. The second chapter, coauthored with Julio Romero, studies how taxes affect small formal firms\u27 entrance decision, the probability of survival, employment and average per-worker compensation. It exploits variation in tax treatment from a cohort-based, tax breaks program implemented in Colombia in 2010. Exploiting the fact that to qualify firms must have registered after December 31, 2010, it compares firms created soon before the cut-off date, to firms created soon after. It finds the availability of the tax breaks did not affect any of the outcomes considered. The third chapter, coauthored with Amy Ellen Schwartz, studies whether exposure to neighborhood violence causes school absenteeism. Exploiting variation in the timing of violent crimes, it compares absenteeism days immediately after exposure, to days immediately before. It finds an increase in average absenteeism after exposure of 5% to 10%. The response is statistically significant for both genders, most race/ethnic groups, and grade levels, and varies by violent crime type, being stronger for cases of exposure to homicides. Students exposed multiple times respond strongly to a second event, regardless of the violent crime type, but not to the subsequent ones

Esfuerzo fiscal municipal en Guatemala

En este trabajo se analiza el esfuerzo fiscal que realizan los municipios guatemaltecos sobre el recaudo de su principal ingreso tributario, el Impuesto Único Sobre Inmuebles (IUSI). Los resultados del estudio indican que el esfuerzo fiscal municipal es bajo y lejano a su potencial en el caso del IUSI. En gran parte, esta situación se origina por la subvaloración de los avalúos catastrales, la cual se produce principalmente por tres razones: la alta tasa de descuento que se aplica a los valores comerciales; la escasa capacidad local para realizar los avalúos, que lleva a que la práctica común sean los auto avalúos sin verificación alguna, y el pobre registro de los bienes inmuebles. A su vez, el análisis de la información permite afirmar que la recaudación del IUSI registra una distribución espacial muy desigual: una alta concentración alrededor del área metropolitana de la ciudad capital y un pobre desempeño del resto del país. Existe un espacio importante para aumentar la recaudación del IUSI a través de la optimización del registro, la actualización de los avalúos, algunos cambios en las regulaciones vigentes y mejoras en la administración del tributomapas, gráficos, tablas.Incluye referencias bibliográficas (páginas 37-40)

A dispatching-fuzzy ahp-topsis model for scheduling flexible job-shop systems in industry 4.0 context

Scheduling flexible job-shop systems (FJSS) has become a major challenge for different smart factories due to the high complexity involved in NP-hard problems and the constant need to satisfy customers in real time. A key aspect to be addressed in this particular aim is the adoption of a multi-criteria approach incorporating the current dynamics of smart FJSS. Thus, this paper proposes an integrated and enhanced method of a dispatching algorithm based on fuzzy AHP (FAHP) and TOPSIS. Initially, the two first steps of the dispatching algorithm (identification of eligible operations and machine selection) were implemented. The FAHP and TOPSIS methods were then integrated to underpin the multi-criteria operation selection process. In particular, FAHP was used to calculate the criteria weights under uncertainty, and TOPSIS was later applied to rank the eligible operations. As the fourth step of dispatching the algorithm, the operation with the highest priority was scheduled together with its initial and final time. A case study from the smart apparel industry was employed to validate the effectiveness of the proposed approach. The results evidenced that our approach outperformed the current company’s scheduling method by a median lateness of 3.86 days while prioritizing high-throughput products for earlier delivery. View Full-Tex

Incidental description of crop contents of the Mexican Parrotlet (Forpus cyanopygius)

Little is known on the ecology of the Mexican Parrotlet (Forpus cyanopygius), an endemic species of western Mexico. Here, we present the first diet report for this species based on crop contents of three individuals that died following impact with a metallic structure. The individuals presented a crop full of 3,015 to 5,400 seeds from Ficus insipida. Figs are an important resource for many vertebrate species and is a food resource reported in the diet of many psittacines. Our report highlights the importance of gathering incidental information to fill knowledge-gaps for poorly known species and enable better conservation planning

Temas de bioética ambiental

Poner la mirada bioética en lo ambiental es plantearse radical- mente la pregunta por el origen y el sentido de todo cuanto existe, con el rigor interdisciplinario de las ciencias que incluyen el volver al mito, a la leyenda, y a las bellmsimas creencias ancestrales. Es toparse el ser humano con la alteridad, con lo otro diferente al +yo; pero hecho de lo mismo, y sentirse profundamente interpelado por las voces silentes de todos los seres que comparten con miritos pares la casa terrenal. Es descubrir con veneracisn y regocijo espiritual el Dios oculto en el mis- terio de la vida, e hincarse de rodillas para pedir su bendicisn. Es unir el Cielo con la Tierra, con la absoluta conviccisn de que no hay Cielo sin Tierra. en smntesis, la mirada bioitica de la ecologma nos hace trascender la inmediatez de lo concreto, para encontrar en ello la validez de lo universal que lo conforma. La vida humana cobra sentido al desvelar el sentido del mundo. Al descubrir felizmente la luminosa unidad del ser en la polmcroma diversidad de todo cuanto existe

Coefficient shifts in geographical ecology: an empirical evaluation of spatial and non-spatial regression

Copyright © 2009 The Authors. Copyright © ECOGRAPHY 2009.A major focus of geographical ecology and macro ecology is to understand the causes of spatially structured ecological patterns. However, achieving this understanding can be complicated when using multiple regressions, because the relative importance of explanatory variables, as measured by regression coefficients, can shift depending on whether spatially explicit or non-spatial modelling is used. However, the extent to which coefficients may shift and why shifts occur are unclear. Here, we analyze the relationship between environmental predictors and the geographical distribution of species richness, body size, range size and abundance in 97 multi-factorial data sets. Our goal was to compare standardized partial regression coefficients of non-spatial ordinary least squares regressions (i.e. models fitted using ordinary least squares without taking autocorrelation into account; “OLS models” hereafter) and eight spatial methods to evaluate the frequency of coefficient shifts and identify characteristics of data that might predict when shifts are likely. We generated three metrics of coefficient shifts and eight characteristics of the data sets as predictors of shifts. Typical of ecological data, spatial autocorrelation in the residuals of OLS models was found in most data sets. The spatial models varied in the extent to which they minimized residual spatial autocorrelation. Patterns of coefficient shifts also varied among methods and datasets, although the magnitudes of shifts tended to be small in all cases. We were unable to identify strong predictors of shifts, including the levels of autocorrelation in either explanatory variables or model residuals. Thus, changes in coefficients between spatial and non-spatial methods depend on the method used and are largely idiosyncratic, making it difficult to predict when or why shifts occur. We conclude that the ecological importance of regression coefficients cannot be evaluated with confidence irrespective of whether spatially explicit modelling is used or not. Researchers may have little choice but to be more explicit about the uncertainty of models and more cautious in their interpretation

BLOOM: A 176B-Parameter Open-Access Multilingual Language Model

Large language models (LLMs) have been shown to be able to perform new tasks based on a few demonstrations or natural language instructions. While these capabilities have led to widespread adoption, most LLMs are developed by resource-rich organizations and are frequently kept from the public. As a step towards democratizing this powerful technology, we present BLOOM, a 176B-parameter open-access language model designed and built thanks to a collaboration of hundreds of researchers. BLOOM is a decoder-only Transformer language model that was trained on the ROOTS corpus, a dataset comprising hundreds of sources in 46 natural and 13 programming languages (59 in total). We find that BLOOM achieves competitive performance on a wide variety of benchmarks, with stronger results after undergoing multitask prompted finetuning. To facilitate future research and applications using LLMs, we publicly release our models and code under the Responsible AI License

Global disparities in surgeons’ workloads, academic engagement and rest periods: the on-calL shIft fOr geNEral SurgeonS (LIONESS) study

: The workload of general surgeons is multifaceted, encompassing not only surgical procedures but also a myriad of other responsibilities. From April to May 2023, we conducted a CHERRIES-compliant internet-based survey analyzing clinical practice, academic engagement, and post-on-call rest. The questionnaire featured six sections with 35 questions. Statistical analysis used Chi-square tests, ANOVA, and logistic regression (SPSS® v. 28). The survey received a total of 1.046 responses (65.4%). Over 78.0% of responders came from Europe, 65.1% came from a general surgery unit; 92.8% of European and 87.5% of North American respondents were involved in research, compared to 71.7% in Africa. Europe led in publishing research studies (6.6 ± 8.6 yearly). Teaching involvement was high in North America (100%) and Africa (91.7%). Surgeons reported an average of 6.7 ± 4.9 on-call shifts per month, with European and North American surgeons experiencing 6.5 ± 4.9 and 7.8 ± 4.1 on-calls monthly, respectively. African surgeons had the highest on-call frequency (8.7 ± 6.1). Post-on-call, only 35.1% of respondents received a day off. Europeans were most likely (40%) to have a day off, while African surgeons were least likely (6.7%). On the adjusted multivariable analysis HDI (Human Development Index) (aOR 1.993) hospital capacity > 400 beds (aOR 2.423), working in a specialty surgery unit (aOR 2.087), and making the on-call in-house (aOR 5.446), significantly predicted the likelihood of having a day off after an on-call shift. Our study revealed critical insights into the disparities in workload, access to research, and professional opportunities for surgeons across different continents, underscored by the HDI