A new approach to social assistance : Latin America's experience with conditional cash transfer programs

Conditional cash transfers are a departure from more traditional approaches to social assistance, that represents an innovative, and increasingly popular channel for the delivery of social services. Conditional cash transfers provide money to poor families, contingent upon certain behavior, usually investments in human capital, such as sending children to school, or bringing them to health centers on a regular basis. They seek both to address traditional short-term income support objectives, as well as to promote the longer-term accumulation of human capital, by serving as a demand-side complement to the supply of health, and education services. Evaluation results from a first generation of programs reveal that this innovative design has been quite successful in addressing many of the criticisms of social assistance, such as poor poverty targeting, disincentive effects, and limited welfare impacts. There is clear evidence of success from programs in Brazil, Colombia, Mexico and Nicaragua in increasing enrollment rates, improving preventive health care and raising household consumption. Despite this promising evidence, many questions remain unanswered about conditional cash transfer programs, including the replicability of their success under different conditions, their role within a broader social protection system, and their long-term effectiveness in preventing the inter- generational transmission of poverty. One of the main challenges facing policymakers today is how to build off of the established success of conditional cash transfer programs, to tackle the more difficult issues of improving the quality of health, and education services, and providing a more holistic approach to both social protection, and chronic poverty.Poverty Assessment,Poverty Impact Evaluation,Health Monitoring&Evaluation,Services&Transfers to Poor,Rural Poverty Reduction

On the origins of approximations for stochastic chemical kinetics

This paper considers the derivation of approximations for stochastic chemical kinetics governed by the discrete master equation. Here, the concepts of (1) partitioning on the basis of fast and slow reactions as opposed to fast and slow species and (2) conditional probability densities are used to derive approximate, partitioned master equations, which are Markovian in nature, from the original master equation. Under different conditions dictated by relaxation time arguments, such approximations give rise to both the equilibrium and hybrid (deterministic or Langevin equations coupled with discrete stochastic simulation) approximations previously reported. In addition, the derivation points out several weaknesses in previous justifications of both the hybrid and equilibrium systems and demonstrates the connection between the original and approximate master equations. Two simple examples illustrate situations in which these two approximate methods are applicable and demonstrate the two methods' efficiencies

North-South knowledgesharing on incentive-based conditional cash transfer programs

Over the last decade, Conditional Cash Transfer (CCT) programs have become one of the most widely adopted anti-poverty initiatives in the developing world. Inspired particularly by Mexico's successful program, CCTs are viewed as an effective way to provide basic income support while building children's human capital. These programs have had a remarkable global expansion, from a handful programs in the late 1990s to programs in close to 30 countries today, including a demonstration program in the United States. In contrast to many other safety net programs in developing countries, CCTs have been closely studied and well evaluated, creating both a strong evidence base from which to inform policy decisions and an active global community of practice. This paper first reviews the emergence of CCTs in the context of a key theme in welfare reform, notably using incentives to promote human capital development, going beyond the traditional focus on income support. The paper then examines what has been learned to date from the experience with CCTs in the South and raises a series of questions concerning the relevance and replicability of these lessons in other contexts. The paper concludes with a call for further knowledge sharing in two areas: between the North and South as the experience with welfare reform and CCTs in particular expands, and between behavioral science and welfare policy.Safety Nets and Transfers,Rural Poverty Reduction,Population Policies,Health Monitoring&Evaluation,Labor Policies

Evaluating the impact of conditional cash transfer programs : lessons from Latin America

Unlike most development initiatives, conditional cash transfer programs recently introduced in the Latin America and the Caribbean region have been subject to rigorous evaluations of their effectiveness. These programs provide money to poor families, conditional on certain behavior, usually investments in human capital-such as sending children to school or bringing them to health centers on a regular basis. Rawlings and Rubio review the experience in evaluating the impact of these programs, exploring the application of experimental and quasi-experimental evaluation methods and summarizing results from programs launched in Brazil, Honduras, Jamaica, Mexico, and Nicaragua. Evaluation results from the first generation of programs in Brazil, Mexico, and Nicaragua show that conditional cash transfer programs are effective in promoting human capital accumulation among poor households. There is clear evidence of success in increasing enrollment rates, improving preventive health care, and raising household consumption. Despite this promising evidence, many questions remain unanswered about the impact of conditional cash transfer programs, including those concerning their effectiveness under different country conditions and the sustainability of the welfare impacts.Public Health Promotion,Poverty Monitoring&Analysis,Poverty Impact Evaluation,Health Monitoring&Evaluation,Health Systems Development&Reform,Poverty Monitoring&Analysis,Poverty Impact Evaluation,Health Monitoring&Evaluation,Poverty Assessment,Health Systems Development&Reform

Stochastic simulation of catalytic surface reactions in the fast diffusion limit

The master equation of a lattice gas reaction tracks the probability of visiting all spatial configurations. The large number of unique spatial configurations on a lattice renders master equation simulations infeasible for even small lattices. In this work, a reduced master equation is derived for the probability distribution of the coverages in the infinite diffusion limit. This derivation justifies the widely used assumption that the adlayer is in equilibrium for the current coverages and temperature when all reactants are highly mobile. Given the reduced master equation, two novel and efficient simulation methods of lattice gas reactions in the infinite diffusion limit are derived. The first method involves solving the reduced master equation directly for small lattices, which is intractable in configuration space. The second method involves reducing the master equation further in the large lattice limit to a set of differential equations that tracks only the species coverages. Solution of the reduced master equation and differential equations requires information that can be obtained through short, diffusion-only kinetic Monte Carlo simulation runs at each coverage. These simulations need to be run only once because the data can be stored and used for simulations with any set of kinetic parameters, gas-phase concentrations, and initial conditions. An idealized CO oxidation reaction mechanism with strong lateral interactions is used as an example system for demonstrating the reduced master equation and deterministic simulation techniques

Two classes of quasi-steady-state model reductions for stochastic kinetics

The quasi-steady-state approximation (QSSA) is a model reduction technique used to remove highly reactive species from deterministic models of reaction mechanisms. In many reaction networks the highly reactive intermediates (QSSA species) have populations small enough to require a stochastic representation. In this work we apply singular perturbation analysis to remove the QSSA species from the chemical master equation for two classes of problems. The first class occurs in reaction networks where all the species have small populations and the QSSA species sample zero the majority of the time. The perturbation analysis provides a reduced master equation in which the highly reactive species can sample only zero, and are effectively removed from the model. The reduced master equation can be sampled with the Gillespie algorithm. This first stochastic QSSA reduction is applied to several example reaction mechanisms (including Michaelis-Menten kinetics) [Biochem. Z. 49, 333 (1913)]. A general framework for applying the first QSSA reduction technique to new reaction mechanisms is derived. The second class of QSSA model reductions is derived for reaction networks where non-QSSA species have large populations and QSSA species numbers are small and stochastic. We derive this second QSSA reduction from a combination of singular perturbation analysis and the Omega expansion. In some cases the reduced mechanisms and reaction rates from these two stochastic QSSA models and the classical deterministic QSSA reduction are equivalent; however, this is not usually the case

Gender, race, and heterogeneous effects of epidemic malaria on human capital and income

This article investigates the impact of exposure to a serious, unusual, and unforeseen malaria epidemic in northeast Brazil in 1938–40 on subsequent human capital attainment and income. Arguing the event was exogenous, the article exploits cohort and regional heterogeneity in exposure to identify effects. Results are consistent with differential mortality rates according to gender and socioeconomic status, such that heterogeneous selection and scarring effects are observed. Analyzing by gender alone, positive (selection) effects are found for men, and mixed (positive and negative) effects for women. Allowing for heterogeneity by race, selection effects persist for men. In contrast, positive (selection) effects are observed for nonwhite women, and negative (scarring) effects for white women. Results contribute to evidence suggesting that exposure to negative environmental shocks affects human capital attainment, while also suggesting it heterogeneously affects cohort composition

Unified Models of Molecular Emission from Class 0 Protostellar Outflow Sources

Low mass star-forming regions are more complex than the simple spherically symmetric approximation that is often assumed. We apply a more realistic infall/outflow physical model to molecular/continuum observations of three late Class 0 protostellar sources with the aims of (a) proving the applicability of a single physical model for all three sources, and (b) deriving physical parameters for the molecular gas component in each of the sources. We have observed several molecular species in multiple rotational transitions. The observed line profiles were modelled in the context of a dynamical model which incorporates infall and bipolar outflows, using a three dimensional radiative transfer code. This results in constraints on the physical parameters and chemical abundances in each source. Self-consistent fits to each source are obtained. We constrain the characteristics of the molecular gas in the envelopes as well as in the molecular outflows. We find that the molecular gas abundances in the infalling envelope are reduced, presumably due to freeze-out, whilst the abundances in the molecular outflows are enhanced, presumably due to dynamical activity. Despite the fact that the line profiles show significant source-to-source variation, which primarily derives from variations in the outflow viewing angle, the physical parameters of the gas are found to be similar in each core.Comment: MNRAS 12 pages, 16 figure

The stochastic quasi-steady-state assumption: Reducing the model but not the noise

Highly reactive species at small copy numbers play an important role in many biological reaction networks. We have described previously how these species can be removed from reaction networks using stochastic quasi-steady-state singular perturbation analysis (sQSPA). In this paper we apply sQSPA to three published biological models: the pap operon regulation, a biochemical oscillator, and an intracellular viral infection. These examples demonstrate three different potential benefits of sQSPA. First, rare state probabilities can be accurately estimated from simulation. Second, the method typically results in fewer and better scaled parameters that can be more readily estimated from experiments. Finally, the simulation time can be significantly reduced without sacrificing the accuracy of the solution

Cervical Cancer Screening in the LGBTQ+ Community: Dispelling Common Misconceptions and Improving Patient Comfort

LGBTQ+ patients are more likely to forgo cervical cancer screening due to common misconceptions/misguidance about who needs screening and increased likelihood to experience emotional and/or physical discomfort during screening visits. This project aims to educate LGBTQ+ patients about cervical cancer screening and provide them with tools to improve their experiences during screening visits.https://scholarworks.uvm.edu/fmclerk/1910/thumbnail.jp