Concept and Unintended Consequences of Weather Index Insurance: The Case of Mexico

Recently, Weather Index Insurance (WII) has received considerable attention as a tool to insure farmers against weather related risks, particularly in developing countries. Donor organizations, local governments, insurance companies, development economists as well as agricultural economists are discussing the costs and benefits of WII. While the literature on WII has mainly focused on many cases in Africa and Asia, in this article we analyze the WII program in Mexico, which is one of the largest WII programs worldwide. In this context we discuss potentially important spill-over effects on related markets which so far have not been considered in the academic literature. First, we argue that WII creates disincentives to invest in other non-insured crops leading to potential overspecialization and monoculture. Secondly, WII generates disincentives to invest in irrigation systems because farmers are insured only as long as production takes place on non-irrigated land. Third, in case of catastrophic events food prices can potentially inflate with indemnity payments at the expense of the uninsured poor. We also suggest that in Mexico the thresholds of the weather index be (continuously) re-calibrated in order to adjust for the development of drought resistant seeds. Finally, the index could relatively easily be extended to account for precipitation variances. We argue that these factors and spillover effects should be accounted for in cost benefit analysis of WII.Weather Index Insurance, policy evaluation, Mexico

A New Materials and Design Approach for Roads, Bridges, Pavement, and Concrete

Increased understanding of demand for transport energy and how to improve road pavement materials would enable decision makers to make environmental, financial, and other positive changes in future planning and design of roads, bridges, and other important transportation structures. This research comprises three studies focused on pavement materials and a fourth study that examines energy demand within the road transportation sector. These studies are as follows: 1. A techno-economic study of ground tire rubber as an asphalt modifier; 2. A computational fluid dynamics analysis comparing the urban heat island effect of two different pavement materials – asphalt and Portland Cement Concrete; 3. A new approach that modifies the surface of ground tire rubber using low-cost chemicals and treatment methods to be used in asphalt applications; and 4. Analysis of road transport energy demand in California and the United States. The findings of these studies include that 1. GTR is an effective and economically suitable additive for modified asphalt, 2. the suitability of PCC pavements in urban settings should be reexamined, 3. Surface modification of GTR materials can improve compatibilization of particles for the manufacture of asphalt materials, and 4. gasoline sales are generally price inelastic in both the U.S. and California. Ultimately, these four studies improve understanding of road pavement materials and transport energy demand. They lay out important information about the future of the relationship between materials and design in the transportation industry. These findings may be used by engineers, policymakers, and others in the industry to better consider implications of decisions involved in design, creation, and modification of structures using pavement and concrete, including roads, bridges, etc

Case Mix, Costs, and Outcomes: Differences Between Faculty and Community Services in a University Hospital

In order to gain insight into the possible consequences of prospective payment for university hospitals, we studied 2,025 admissions to the faculty and community services of a university hospital, measuring differences in case mix, costs, and outcomes. The faculty service case mix was disproportionately weighted toward the more costly diagnoses, but even after adjustment for diagnosis-related groups (DRGs), costs were 11 percent higher on the faculty service. The differential was proportionately greater for diagnostic costs than for routine or treatment costs, and the differential was particularly large (70 percent) for patients with a predicted probability of death (DTHRISK) of .25 or greater.The in-hospital mortality rate was appreciably lower on the faculty service after adjustment for case mix and patient characteristics. The mortality differential between the two services was particularly large for patients in the high death risk category. Comparison of a matched sample of 51 pairs of admissions from the high death risk category confirmed the above results with respect to costs and in-hospital mortality, but follow-up revealed that the mortality rates were equal for the two services at nine months after discharge.

Why do Economists Disagree About Policy?

This paper reports the results of surveys of specialists in labor economics and public economics at 40 leading research universities in the United States. Respondents provided opinions of policy proposals; quantitative best estimates and 95% confidence intervals for economic parameters; answers to values questions regarding income redistribution, efficiency versus equity, and individual versus social responsibility; and their political party identification. We find considerable disagreement among economists about policy proposals. Their positions on policy are more closely related to their values than to their estimates of relevant economic parameters or to their political party identification. Average best estimates of the economic parameters agree well with the ranges summarized in surveys of relevant literature, but the individual best estimates are usually widely dispersed. Moreover, economists, like experts in many fields, appear more confident of their estimates than the substantial cross-respondent variation in estimates would warrant. Finally although the confidence intervals in general appear to be too narrow, respondents whose best estimates are farther from the median tend to give wider confidence intervals for those estimates.

Mixed retrieval and virtual documents on the World Wide Web

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1997.Includes bibliographical references (leaves 68-70).by Christopher Alan Fuchs.M.Eng

Impaired Translesion Synthesis in Xeroderma Pigmentosum Variant Extracts

Xeroderma pigmentosum variant (XPV) cells are characterized by a cellular defect in the ability to synthesize intact daughter DNA strands on damaged templates. Molecular mechanisms that facilitate replication fork progression on damaged DNA in normal cells are not well defined. In this study, we used single-stranded plasmid molecules containing a single N-2-acetylaminofluorene (AAF) adduct to analyze translesion synthesis (TLS) catalyzed by extracts of either normal or XPV primary skin fibroblasts. In one of the substrates, the single AAF adduct was located at the 3' end of a run of three guanines that was previously shown to induce deletion of one G by a slippage mechanism. Primer extension reactions performed by normal cellular extracts from four different individuals produced the same distinct pattern of TLS, with over 80% of the products resulting from the elongation of a slipped intermediate and the remaining 20% resulting from a nonslipped intermediate. In contrast, with cellular extracts from five different XPV patients, the TLS reaction was strongly reduced, yielding only low amounts of TLS via the nonslipped intermediate. With our second substrate, in which the AAF adduct was located at the first G in the run, thus preventing slippage from occurring, we confirmed that normal extracts were able to perform TLS 10-fold more efficiently than XPV extracts. These data demonstrate unequivocally that the defect in XPV cells resides in translesion synthesis independently of the slippage proces

Gaps and forks in DNA replication: Rediscovering old models

Most current models for replication past damaged lesions envisage that translesion synthesis occurs at the replication fork. However older models suggested that gaps were left opposite lesions to allow the replication fork to proceed, and these gaps were subsequently sealed behind the replication fork. Two recent articles lend support to the idea that bypass of the damage occurs behind the fork. In the first paper, electron micrographs of DNA replicated in UV-irradiated yeast cells show regions of single-stranded DNA both at the replication forks and behind the fork, the latter being consistent with the presence of gaps in the daughter-strands opposite lesions. The second paper describes an in vitro DNA replication system reconstituted from purified bacterial proteins. Repriming of synthesis downstream from a blocked fork occurred not only on the lagging strand as expected, but also on the leading strand, demonstrating that contrary to widely accepted beliefs, leading strand synthesis does not need to be continuous