Kathy Baylis

Price Dispersion on the Internet: Good Firms and Bad Firms

Internet firms charge a wide range of prices for homogeneous products, and high-priced firms remain high-priced and low-priced firms remain low-priced over long periods. One explanation is that high-price firms are charging a premium for superior service. An alternative, price-dispersion explanation is that firms vary the prices for informed and uniformed consumers (Salop and Stiglitz, 1977) or serious shoppers and others (Wilde and Schwartz, 1979). The pricing pattern for a digital camera and a flatbed scanner is consistent with the price-dispersion model and inconsistent with the service-premium hypothesis.

Fast-Food Consumption and the Ban on Advertising Targeting Children: The Quebec Experience

Amid growing concerns about childhood obesity and the associated health risks, several countries are considering banning fast-food advertising targeting children. In this article, the authors study the effect of such a ban in the Canadian province of Quebec. Using household expenditure survey data from 1984 to 1992, authors examine whether expenditure on fast food is lower in those groups affected by the ban than in those that are not. The authors use a triple difference-indifference methodology by appropriately defining treatment and control groups and find that the bans effectiveness is not a result of the decrease in fast food expenditures per week but rather of the decrease in purchase propensity by 13% per week. Overall, the authors estimate that the ban reduced fast-food consumption by Us

A spatially explicit estimate of avoided forest loss.

88 million per year. The study suggests that advertising bans can be effective provided media markets do not overlap.

Encuesta nacional sobre la pérdida anual de colmenas de abejas manejadas durante 2014–2015 en los EEUU

With the potential expansion of forest conservation programs spurred by climate-change agreements, there is a need to measure the extent to which such programs achieve their intended results. Conventional methods for evaluating conservation impact tend to be biased because they do not compare like areas or account for spatial relations. We assessed the effect of a conservation initiative that combined designation of protected areas with payments for environmental services to conserve over wintering habitat for the monarch butterfly (Danaus plexippus) in Mexico. To do so, we used a spatial-matching estimator that matches covariates among polygons and their neighbors. We measured avoided forest loss (avoided disturbance and deforestation) by comparing forest cover on protected and unprotected lands that were similar in terms of accessibility, governance, and forest type. Whereas conventional estimates of avoided forest loss suggest that conservation initiatives did not protect forest cover, we found evidence that the conservation measures are preserving forest cover. We found that the conservation measures protected between 200 ha and 710 ha (3-16%) of forest that is high-quality habitat for monarch butterflies, but had a smaller effect on total forest cover, preserving between 0 ha and 200 ha (0-2.5%) of forest with canopy cover >70%. We suggest that future estimates of avoided forest loss be analyzed spatially to account for how forest loss occurs across the landscape. Given the forthcoming demand from donors and carbon financiers for estimates of avoided forest loss, we anticipate our methods and results will contribute to future studies that estimate the outcome of conservation efforts.

Standard Epidemiological Methods to Understand and Improve Apis Mellifera Health

Declines of pollinators and high mortality rates of honey bee colonies are a major concern, both in the USA and globally. Long-term data on summer, winter, and annual colony losses improve our understanding of forces shaping the viability of the pollination industry. Since the mass die-offs of colonies in the USA during the winter of 2006–2007, generally termed “Colony Collapse Disorder” (CCD), annual colony loss surveys have been conducted. These surveys gage colony losses among beekeepers of all operation sizes, recruited to participate via regional beekeeping organizations, phone calls, and postal mail. In the last three years, these surveys include summer and annual losses in addition to winter losses. Winter losses in this most recent survey include 5,937 valid participants (5,690 backyard, 169 sideline, and 78 commercial beekeepers), collectively managing 414,267 colonies on 1 October 2014 and constituting 15.1% of the estimated 2.74 million managed colonies in the USA. Annual losses are typically higher than either winter or summer losses, as they calculate losses over the entire year. Total reported losses were 25.3% [95% CI 24.7–25.9%] over the summer, 22.3% [95% CI 21.9–22.8%] over the winter, and 40.6% [95% CI 40.0–41.2%] for the entire 2014–2015 beekeeping year. Average losses were 14.7% [95% CI 14.0–15.3%] over the summer, 43.7% [95% CI 42.8–44.6%] over the winter, and 49.0% [95% CI 48.1–50.0%] over the entire year. While total winter losses were lower in 2014–2015 than in previous years, summer losses remained high, resulting in total annual colony losses of more than 40% during the survey period. This was the first year that total losses were higher in the summer than in the winter, explained in large part by commercial beekeepers reporting losses of 26.2% of their managed colonies during summer, compared to 20.5% during winter. Self-identified causes of overwintering mortality differed by operation size, with smaller backyard beekeepers generally indicating colony management issues (e.g., starvation, weak colony in the fall), in contrast to commercial beekeepers who typically emphasize parasites or factors outside their control (e.g., varroa, nosema, queen failure). More than two-thirds of all beekeepers (67.3%) had higher colony losses than they deemed acceptable.

How effective are biodiversity conservation payments in Mexico

Summary In this paper, we describe the use of epidemiological methods to understand and reduce honey bee morbidity and mortality. Essential terms are presented and defined and we also give examples for their use. Defining such terms as disease, population, sensitivity, and specificity, provides a framework for epidemiological comparisons. The term population, in particular, is quite complex for an organism like the honey bee because one can view “epidemiological unit” as individual bees, colonies, apiaries, or operations. The population of interest must, therefore, be clearly defined. Equations and explanations of how to calculate measures of disease rates in a population are provided. There are two types of study design; observational and experimental. The advantages and limitations of both are discussed. Approaches to calculate and interpret results are detailed. Methods for calculating epidemiological measures such as detection of rare events, associating exposure and disease (Odds Ratio and Relative Risk), and comparing prevalence and incidence are discussed. Naturally, for beekeepers, the adoption of any management system must have economic advantage. We present a means to determine the cost and benefit of the treatment in order determine its net benefit. Lastly, this paper presents a discussion of the use of Hills criteria for inferring causal relationships. This framework for judging cause-effect relationships supports a repeatable and quantitative evaluation process at the population or landscape level. Hills criteria disaggregate the different kinds of evidence, allowing the scientist to consider each type of evidence individually and objectively, using a quantitative scoring method for drawing conclusions. It is hoped that the epidemiological approach will be more broadly used to study and negate honey bee disease.

Spatial Approaches to Panel Data in Agricultural Economics: A Climate Change Application

We assess the additional forest cover protected by 13 rural communities located in the southern state of Chiapas, Mexico, as a result of the economic incentives received through the countrys national program of payments for biodiversity conservation. We use spatially explicit data at the intra-community level to define a credible counterfactual of conservation outcomes. We use covariate-matching specifications associated with spatially explicit variables and difference-in-difference estimators to determine the treatment effect. We estimate that the additional conservation represents between 12 and 14.7 percent of forest area enrolled in the program in comparison to control areas. Despite this high degree of additionality, we also observe lack of compliance in some plots participating in the PES program. This lack of compliance casts doubt on the ability of payments alone to guarantee long-term additionality in context of high deforestation rates, even with an augmented program budget or extension of participation to communities not yet enrolled.

Trade Diversion from Tomato Suspension Agreements

Panel data are used in almost all subfields of the agricultural economics profession. Furthermore, many research areas have an important spatial dimension. This article discusses some of the recent contributions made in the evolving theoretical and empirical literature on spatial econometric methods for panel data. We then illustrate some of these tools within a climate change application using a hedonic model of farmland values and panel data. Estimates for the model are provided across a range of nonspatial and spatial estimators, including spatial error and spatial lag models with fixed and random effects extensions. Given the importance of location and extensive use of panel data in many subfields of agricultural economics, these recently developed spatial panel methods hold great potential for applied researchers.

Emerging Evidence on the Effectiveness of Tropical Forest Conservation

Trade barriers can cause output to be diverted to other countries and into other products. We study the effect of a voluntary price restraint (VPR) on Mexican tomatoes entering the United States. The diversion caused by the VPR is statistically and economically significant - representing over four-fifths of the direct effects of the trade barrier. When the VPR was binding, Mexico exported more tomatoes to Canada, the United States cut back on exports while Canada increased their exports to the United States. The VPR also diverted fresh tomatoes in Mexico into paste production, which was then exported to the United States.

Water-Based Recreational Benefits of Conservation Programs: The Case of Conservation Tillage on U.S. Cropland

The PLOS ONE Collection “Measuring forest conservation effectiveness” brings together a series of studies that evaluate the effectiveness of tropical forest conservation policies and programs with the goal of measuring conservation success and associated co-benefits. This overview piece describes the geographic and methodological scope of these studies, as well as the policy instruments covered in the Collection as of June 2016. Focusing on forest cover change, we systematically compare the conservation effects estimated by the studies and discuss them in the light of previous findings in the literature. Nine studies estimated that annual conservation impacts on forest cover were below one percent, with two exceptions in Mexico and Indonesia. Differences in effect sizes are not only driven by the choice of conservation measures. One key lesson from the studies is the need to move beyond the current scientific focus of estimating average effects of undifferentiated conservation programs. The specific elements of the program design and the implementation context are equally important factors for understanding the effectiveness of conservation programs. Particularly critical will be a better understanding of the causal mechanisms through which conservation programs have impacts. To achieve this understanding we need advances in both theory and methods.