The Effect of Market Structure on Pest Resistance Buildup

In this paper we present a continuous time optimal control analysis of resistance buildup in agricultural chemicals when the supplier is a monopolist. We compare the monopolistic, competitive and socially optimal solutions after establishing the stability of each equilibrium. The central finding is that with a monopolistic supplier, resistance buildup is lower than socially optimal. This directly opposes the standard result in the resistance literature. This implies that policies to manage resistance should vary with the age of the chemical, with no intervention during the lifetime of a patent and an optimal tax once the patent expires.Research Methods/ Statistical Methods,

Payments for Environmental Services: To whom, where, and how much?

In this paper we consider different strategies for implementing a payment for environmental services (PES) program to mitigate deforestation in Mexican common property forests (ejidos). We begin by discussing the policy context within which PES programs find themselves, highlighting other possible interventions to help preserve environmental amenities in Mexico. We then discuss some basic principles of environmental payment schemes, formalizing these into three that we simulate: payment of the opportunity cost for forests at risks; payment for environmental benefits provided by forests at risk; a flat payment scheme with a cap on allowable hectares, similar to the type of program often applied in developing countries; and a program of opportunity cost payments for forest at risk with highest environmental benefit per dollar paid. We find that, of these three, the last is most efficient and the second most egalitarian. We also repeat a simulation of the third scheme using predicted, rather than actual risk, which circumvents the problem of strategic behavior on the part of recipient communities but introduces some error into the targeting process. Finally, we consider the characteristics of communities that receive payments from the most efficient program, finding that larger and more remote ejidos receive the lion's share of the budget, but that payments to them are not necessarily more efficient. This scheme also gives more, though smaller on a per capita basis, payments to poor and indigenous communities, where they are more efficient than those to non-poor and non-indigenous ejidos.Environmental Economics and Policy,

Remotely Incorrect? Accounting for Nonclassical Measurement Error in Satellite Data on Deforestation

Research relying on remotely sensed data on land use and deforestation has exploded in recent years. While satellite-based measures have clear advantages in terms of coverage, the presence of measurement error within these products is often overlooked. Here, we detail the econometric implications of these errors when analyzing the determinants of binary measures of deforestation or forest cover. We then discuss estimators that exploit knowledge of the remote sensing process to obtain consistent estimates. Finally, we assess our estimators via simulation and an impact evaluation of a conservation program in Mexico. We find that both geography and characteristics of the raw data can lead to systematic under-reporting of deforestation. However, accounting for these sources of error, which are common across many satellite-based metrics, can limit the bias from misclassification

Can Government-Controlled Media Cause Social Change? Television and Fertility in India *

Abstract Does exposure to government-controlled media shape social attitudes and behaviors? Governments routinely enlist public broadcasting to advance progressive social change. However, the efficacy of so-called "developmental communications" is unclear. Modernization theorists contend that the media serve as an important instrument of persuasion in poor countries-especially among certain population groups. Yet, where institutionalization is weak, government-controlled outlets are often dominated by ruling-party propaganda, which may induce distrust in the media and its messaging campaigns. To adjudicate which of these propositions holds sway, we investigate television's impact on fertility preferences and behaviors in India. Exploiting unique data, as well as plausibly exogenous variation in TV ownership due to electromagnetic wave refraction, we show that exposure to India's monopolistic state broadcaster, Doordarshan, caused women to desire fewer children-especially fewer girls-while increasing family planning discussions and contraceptive use. The results demonstrate that even biased state media can engender far-reaching societal transformation. * We than

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Title: A Tale of Two Communities: Explaining Deforestation in Mexico A Tale of Two Communities: Explaining deforestation in Mexico

Abstract: Explaining land use change in Mexico requires understanding the behavior of the local institutions involved. We develop two theories to explain deforestation in communities with and without forestry projects, where the former involves a process of side payments to non-members of the community and the latter of partial cooperation among community members. Data collected in 2002 combined with satellite imagery are used to test these theories. For the forestry villages, we establish a positive relationship between the distribution of profits as dividends instead of public goods and forest loss. For communities not engaged in forestry projects, deforestation is largely related to the ability of the community to induce the formation of a coalition of members that cooperates in not encroaching. This happens more easily in smaller communities with experienced leaders. A disturbing result of the analysis is that deforestation is higher when a community engages in forestry projects, even after properly accounting for self-selection into this activity. This suggests that forestry projects as they now exist in Mexico are not sustainable and contribute to the deforestation problem. Explaining land use change in Mexico requires understanding the behavior of the local institutions involved. We develop two theories to explain deforestation in communities with and without forestry projects, where the former involves a process of side payments to non-members of the community and the latter of partial cooperation among community members. Data collected in 2002 combined with satellite imagery are used to test these theories. For the forestry villages, we establish a positive relationship between the distribution of profits as dividends instead of public goods and forest loss. For communities not engaged in forestry projects, deforestation is largely related to the ability of the community to induce the formation of a coalition of members that cooperates in not encroaching. This happens more easily in smaller communities with experienced leaders. A disturbing result of the analysis is that deforestation is higher when a community engages in forestry projects, even after properly accounting for self-selection into this activity. This suggests that forestry projects as they now exist in Mexico are not sustainable and contribute to the deforestation problem

An exploration of the positive effect of inequality on common property forests

This paper analyzes the household level forces driving the positive impact of inequality on common property forest cover in Mexico. A game theoretic model demonstrates that when common property goods are complementary to private inputs in production, an increase in wealth inequality can lead to a decrease in exploitation of the commons. Data from 350 Mexican common properties show that as inequality increases, those on the lower end of the land distribution are less likely to use the commons. The data also show a negative correlation between inequality and poverty. Alternative hypotheses for these results are considered.