Dyer G.A.,Abt Assoc. Inc. |
Dyer G.A.,Colegio de Mexico |
Lopez-Feldman A.,Research Center y Docencia Economicas |
Yunez-Naude A.,Colegio de Mexico |
Taylor J.E.,University of California at Davis
Proceedings of the National Academy of Sciences of the United States of America | Year: 2014
Crop genetic diversity is an indispensable resource for farmers and professional breeders responding to changing climate, pests, and diseases. Anecdotal appraisals in centers of crop origin have suggested serious threats to this diversity for over half a century. However, a nationwide inventory recently found all maize races previously described for Mexico, including some formerly considered nearly extinct. A flurry of social studies seems to confirm that farmers maintain considerable diversity. Here, we compare estimates of maize diversity from case studies over the past 15 y with nationally and regionally representative matched longitudinal data from farmers across rural Mexico. Our findings reveal an increasing bias in inferences based on case study results and widespread loss of diversity. Cross-sectional, case study data suggest that farm-level richness has increased by 0.04 y-1nationwide; however, direct estimates using matched longitudinal data reveal that richness dropped -0.04 y-1between 2002 and 2007, from 1.43 to 1.22 varieties per farm. Varietal losses occurred across regions and altitudinal zones, and regardless of farm turnover within the sector. Extinction of local maize populations may not have resulted in an immediate loss of alleles, but low varietal richness and changes in maize's metapopulation dynamics may prevent farmers from accessing germplasm suitable to a rapidly changing climate. Declining yields could then lead farmers to leave the sector and result in a further loss of diversity. Similarities in research approaches across crops suggest that methodological biases could conceal a loss of diversity at other centers of crop origin.
Lichtenberg E.,University of Maryland University College |
Smith-Ramirez R.,Research Center y Docencia Economicas
American Journal of Agricultural Economics | Year: 2011
We examine whether subsidies for conservation on working farmland induce farmers to expand cultivation on more vulnerable land, potentially offsetting reductions in environmental spillovers, using a switching regression model with endogenous switching and censored endogenous variables applied to Maryland farm-level data. We find no indication that cost share awards are targeted toward water quality improvements. Receipt of cost sharing increases conservation practice adoption but not the shares of land allocated to conservation, implying little adverse selection in awards. Cost sharing decreases the share of land allocated to vegetative cover, so that environmental quality improvements from conservation are likely offset to some degree. © 2010 The Author. Published by Oxford University Press on behalf of the Agricultural and Applied Economics Association. All rights reserved.
Chakraborti L.,Research Center y Docencia Economicas
Journal of Environmental Economics and Management | Year: 2016
In this paper we show that plants respond to downstream ambient water quality after controlling for permitted levels of pollution. We find if past water quality declines by one percent, plants reduce current pollution by 0.35 percent. The magnitude of this coefficient is comparable to the coefficient on permitted discharge levels i.e. regulatory stringency itself. Results are consistent with two mechanisms. First, a decline in water quality may lead to more stringent permits that would raise the cost of abatement of a plant significantly. Second, the plant is likely to be subject to increased public pressure in response to poor water quality. Indeed, as expected, the impact of water quality becomes stronger in locations with higher median household income, higher percent carpooling to work, or lower percent of manufacturing employment but surprisingly with lower median age of residents, lower percent with bachelor[U+05F3]s degree or higher percent of families with children. © 2016 Elsevier Inc.
Vilalta C.J.,Research Center y Docencia Economicas
Applied Geography | Year: 2010
The two objectives of this study were to determine the spatial patterns of arrests for drug possession and to identify the socioeconomic correlates of drug hotspots in Mexico City. Spatial statistics allowed detection of four Marijuana and three Cocaine hotspots. Statistical correlation and difference tests showed Marijuana hotspots to have better housing conditions and more female-headed households. No socioeconomic correlates could be established for Cocaine hotspots. These spatial patterns are worth further causal studies on this important issue. To this point, results make more convincing the argument that crime solutions can be found in a combination of urban planning, social development, and policing strategies. © 2009 Elsevier Ltd. All rights reserved.
Gil-Garcia J.R.,Research Center y Docencia Economicas
Information Polity | Year: 2012
Information technologies (IT) can now be considered one of the key components of government administrative reform. The potential is even greater when working across organizational boundaries. Unfortunately, inter-agency collaboration appears to face an even greater number of challenges than similar IT initiatives within a single organization. The challenges include data and technological incompatibility, the lack of institutional incentives to collaborate, and the politics and power struggles around a pervasive silo structure in most governments, among many others. This paper argues that there are clear trends towards greater inter-organizational collaboration, information sharing, and integration, which could lead, in the near future, to what might be called a smart State. The paper starts discussing the promises and challenges that have already been identified for government information sharing and integration initiatives. Then it describes two trends in terms of inter-organizational collaboration and information technologies in government settings. The paper ends by providing reflections about the technical and political feasibility, as well as the social desirability, of an integrated virtual State in which the executive, legislative, and judicial branches1 are actively collaborating and sharing information through the use of advanced information technologies, sophisticated coordination mechanisms, shared physical infrastructure, and, potentially, new organizational and institutional arrangements. © 2012 - IOS Press and the authors. All rights reserved.
Dyer G.A.,Colegio de Mexico |
Lopez-Feldman A.,Research Center y Docencia Economicas
PLoS ONE | Year: 2013
Farmer management of plant germplasm pre-dates crop domestication, but humans' role in crop evolution and diversity remains largely undocumented and often contested. Seemingly inexplicable practices observed throughout agricultural history, such as exchanging or replacing seed, continue to structure crop populations across the developing world. Seed management practices can be construed as events in the life history of crops and management data used to model crop demography, but this requires suitable quantitative data. As a prerequisite to addressing the causes and implications of maize seed management, we describe its patterns of variation across Mexico by drawing from the literature and new analysis. We find that rates of seed replacement, introduction and diffusion differ significantly across regions and altitudinal zones, but interactions among explanatory factors can obscure patterns of variation. The type, source, geographic origin and ownership of seed help explain observed rates. Yet, controlling for the characteristics of germplasm barely reduces interregional differences vastly exceeding variation across elevations. With few exceptions, monotonic altitudinal trends are absent. Causal relationships between management practices and the physical environment could determine farmers' wellbeing and crop conservation in the face of climate change. Scarce and inconsistent data on management nevertheless could prevent an understanding of these relationships. Current conceptions on the management and dynamics of maize diversity are founded on a patchwork of observations in surprisingly few and dissimilar environments. Our estimates of management practices should shed light on differences in maize population dynamics across Mexico. Consistency with previous studies spanning over a decade suggests that common sets of forces are present within large areas, but causal associations remain unknown. The next step in explaining crop diversity should address variation in seed management across space and time simultaneously while identifying farmers' values and motivations as underlying forces. © 2013 Dyer, López-Feldman.
Hancevic P.I.,Research Center y Docencia Economicas
Energy Economics | Year: 2016
This paper measures the impact of the 1990 Clean Air Act Amendments on coal-fired boilers’ productivity and output. The Act led to generating units adopting a number of different pollution abating behaviors, one of which was an input change to lower SO2 emitting coal. A key feature of the production technology is that each boiler is designed to burn a particular variety of coal, with significant deviations from the targeted coal characteristics resulting in productivity losses. Using data for the 1985–1999 period, I present empirical evidence of the policy impact. The main findings are that productivity declined between 1% and 2.5%, on average, and output losses ranged from 1% to 6% for affected boilers, varying across regions and over time. © 2016 Elsevier B.V.
Unger-Saldana K.,Research Center y Docencia Economicas
World Journal of Clinical Oncology | Year: 2014
This critical review of the literature assembles and compares available data on breast cancer clinical stage, time intervals to care, and access barriers in different countries. It provides evidence that while more than 70% of breast cancer patients in most high-income countries are diagnosed in stages I and II, only 20%-50% patients in the majority of low-and middleincome countries are diagnosed in these earlier stages. Most studies in the developed world show an association between an advanced clinical stage of breast cancer and delays greater than three months between symptom discovery and treatment start. The evidence assembled in this review shows that the median of this interval is 30-48 d in high-income countries but 3-8 mo in low-and middle-income countries. The longest delays occur between the first medical consultation and the beginning of treatment, known as the provider interval. The little available evidence suggests that access barriers and quality deficiencies in cancer care are determinants of provider delay in low-and middle-income countries. Research on specific access barriers and deficiencies in quality of care for the early diagnosis and treatment of breast cancer is practically non-existent in these countries, where it is the most needed for the design of cost-effective public policies that strengthen health systems to tackle this expensive and deadly disease. © 2014 Baishideng Publishing Group Inc. All rights reserved.
Pacheco-Vega R.,Research Center y Docencia Economicas
Review of Policy Research | Year: 2015
While a majority of scholarship on the study of transnational advocacy networks (TANs) has focused on the role of value-and-belief-sharing as these networks link activists across nations together, less has been written concerning the role of knowledge exchange among environmental nongovernmental organizations (ENGOs) in helping effect policy change. This article examines how transnational coalitions of ENGOs in North America have helped shape environmental policy across the Canada-U.S.-Mexico borders. In the paper, I explore two cases of nonstate actor mobilization: the North American Pollutant Release, and Transfer Registry Project and the Citizen Submission on Enforcement Matters. In this article, I bridge notions of "soft power" with scholarship on knowledge sharing, thereby showing that nonstate actors use it as a model to build stronger transnational coalitions, effecting pressure on industry and intergovernmental actors, and provide policy input in environmental decision making across borders. © 2015 Policy Studies Organization.
Kiewiet De Jonge C.P.,Research Center y Docencia Economicas
Public Opinion Quarterly | Year: 2015
While political campaigns commonly employ clientelistic mobilization tactics during elections in developing countries, studying vote buying with mass surveys has proven difficult since respondents often will not admit to receiving a gift or favor in exchange for their votes. This study explores the degree to which respondents vary in their reporting of the receipt of goods or favors. Analysis of list experiments included in 10 surveys conducted in eight Latin American countries demonstrates the widespread prevalence of underreporting and shows that it is best predicted by three different sources of question sensitivity. First, bias is greater among respondents with higher levels of education, likely due to greater understanding and awareness of democratic norms about vote buying. Second, since vote buying is often stigmatized as resulting from poverty, those who are particularly sensitive to questions about income also prove to be much more likely to edit their answers. Finally, bias is positively associated with the degree to which the goods distributed violate democratic norms, as bias is smallest in countries in which the gifts consist largely of innocuous campaign materials and items such as clothing and food. The results not only point to probable biases in analyses conducted using direct measures of gift dispensation, but also illuminate how social attitudes about vote buying have spread in different countries in Latin America. © 2015 The Author.