138 research outputs found
THE EFFECT OF QUALITY ASSURANCE POLICIES FOR PROCESSING TOMATOES ON THE DEMAND FOR PESTICIDES
In California, acceptance sampling is used to monitor the quality of processing tomatoes delivered by growers to processors. A proposal to change the current quality assurance policy was recently put forth to reduce the growersÂ’' incentive to use pesticides. In this article we examine the effect of alternative quality assurance policies on profit-maximizing growerÂ’s' demand for pesticides. The results indicate that the demand for pesticides is sensitive to changes in the quality assurance policy and that the proposed policy would reduce the optimal level of pesticide use on processing tomatoes. Disregarding the impacts of quality assurance policy may be the reason that the demand for pesticides has been underestimated so often in the past.Crop Production/Industries,
DESIGNING FOOD SAFETY REGULATIONS: THE EFFECT OF INSPECTION POLICY AND PENALTIES FOR NONCOMPLIANCE ON FOOD PROCESSOR BEHAVIOR
In the United States, federal, state, and local governments are involved with the regulation of the safety of the food supply. Food safety regulations that set standards for food processors usually include inspection policies for monitoring performance and penalties for processors who do not comply with regulatory standards. In this analysis, we examine how penalties and inspection policies interact to influence processor behavior. We distinguish between internal penalties (imposed by the regulator) and external penalties (imposed by the market or by the court). Using a model of the processor's expected annual cost, we find that under a given inspection policy internal penalties are only relevant under specific conditions. For cases in which internal and external penalties can be influenced, we use comparative statics to discover that internal penalties are more economically efficient for motivating processors than external penalties. These results imply that regulators should utilize internal penalties for noncompliance rather that rely on market or court-imposed penalties.Food Consumption/Nutrition/Food Safety,
OPTIMAL GRADE DEFINITIONS FOR MULTIPLE QUALITY CHARACTERISTICS
The growing importance of quality in agricultural markets makes effective segregation and grading essential to efficient marketing strategy. In this paper, we develop an economic model, potentially applicable to many products, to determine optimal segregation strategies based on multiple stochastic quality measures. The model is applied to Oklahoma wheat quality data.Marketing,
Do Inspection and Traceability Provide Incentives for Food Safety?
One of the goals of inspection and traceability is to motivate suppliers to deliver safer food. The ability of these policies to motivate suppliers depends on the accuracy of the inspection, the cost of failing inspection, the cost of causing a foodborne illness, and the proportion of these costs paid by the supplier. We develop a model of the supplier's expected cost as a function of inspection accuracy, the cost of failure, and the proportion of the failure cost that is allocated to suppliers. The model is used to identify the conditions under which the supplier is motivated to deliver uncontaminated lots. Surprisingly, our results show that when safety failure costs can be allocated to suppliers, minimum levels of inspection error are required to motivate a supplier to deliver uncontaminated lots. This result does not hold when costs cannot be allocated to suppliers. As a case study, we use our results to analyze the technical requirements for suppliers of frozen beef to the USDA's Agricultural Marketing Service.diagnostic error, food safety, inspection, sampling error, traceability, Food Consumption/Nutrition/Food Safety,
Traceability, Moral Hazard, and Food Safety
Errors in traceability can significantly impact the moral hazard associated with producing safe food. The effect of moral hazard depends on the proportion of unsafe food costs that can be allocated to the responsible producer, which depends on the efficiency of the traceability system. In this paper, we develop a model that identifies the minimum level of traceability needed to mitigate moral hazard and motivate suppliers to produce safe food. Regulators and consumer can use the results of this research to design regulations and contracts that mitigate moral hazard and motivate producers to deliver safe food.Food safety, traceability, moral hazard, Food Consumption/Nutrition/Food Safety,
Thematically analysing social network content during disasters through the lens of the disaster management lifecycle
Social Networks such as Twitter are often used for disseminating and collecting information during natural disasters. The potential for its use in Disaster Management has been acknowledged. However, more nuanced understanding of the communications that take place on social networks are required to more effectively integrate this information into the processes within disaster management. The type and value of information shared should be assessed, determining the benefits and issues, with credibility and reliability as known concerns. Mapping the tweets in relation to the modelled stages of a disaster can be a useful evaluation for determining the benefits/drawbacks of using data from social networks, such as Twitter, in disaster management.A thematic analysis of tweets' content, language and tone during the UK Storms and Floods 2013/14 was conducted. Manual scripting was used to determine the official sequence of events, and classify the stages of the disaster into the phases of the Disaster Management Lifecycle, to produce a timeline. Twenty-five topics discussed on Twitter emerged, and three key types of tweets, based on the language and tone, were identified. The timeline represents the events of the disaster, according to the Met Office reports, classed into B. Faulkner's Disaster Management Lifecycle framework. Context is provided when observing the analysed tweets against the timeline. This illustrates a potential basis and benefit for mapping tweets into the Disaster Management Lifecycle phases. Comparing the number of tweets submitted in each month with the timeline, suggests users tweet more as an event heightens and persists. Furthermore, users generally express greater emotion and urgency in their tweets.This paper concludes that the thematic analysis of content on social networks, such as Twitter, can be useful in gaining additional perspectives for disaster management. It demonstrates that mapping tweets into the phases of a Disaster Management Lifecycle model can have benefits in the recovery phase, not just in the response phase, to potentially improve future policies and activities
Followback Clusters, Satellite Audiences, and Bridge Nodes: Coengagement Networks for the 2020 US Election
The 2020 United States presidential election was, and has continued to be,
the focus of pervasive and persistent mis- and disinformation spreading through
our media ecosystems, including social media. This event has driven the
collection and analysis of large, directed social network datasets, but such
datasets can resist intuitive understanding. In such large datasets, the
overwhelming number of nodes and edges present in typical representations
create visual artifacts, such as densely overlapping edges and tightly-packed
formations of low-degree nodes, which obscure many features of more practical
interest. We apply a method, coengagement transformations, to convert such
networks of social data into tractable images. Intuitively, this approach
allows for parameterized network visualizations that make shared audiences of
engaged viewers salient to viewers. Using the interpretative capabilities of
this method, we perform an extensive case study of the 2020 United States
presidential election on Twitter, contributing an empirical analysis of
coengagement. By creating and contrasting different networks at different
parameter sets, we define and characterize several structures in this discourse
network, including bridging accounts, satellite audiences, and followback
communities. We discuss the importance and implications of these empirical
network features in this context. In addition, we release open-source code for
creating coengagement networks from Twitter and other structured interaction
data.Comment: Accepted for publication at ICWSM '2
Rapid Diagnostics of Onboard Sequences
Keeping track of sequences onboard a spacecraft is challenging. When reviewing Event Verification Records (EVRs) of sequence executions on the Mars Exploration Rover (MER), operators often found themselves wondering which version of a named sequence the EVR corresponded to. The lack of this information drastically impacts the operators diagnostic capabilities as well as their situational awareness with respect to the commands the spacecraft has executed, since the EVRs do not provide argument values or explanatory comments. Having this information immediately available can be instrumental in diagnosing critical events and can significantly enhance the overall safety of the spacecraft. This software provides auditing capability that can eliminate that uncertainty while diagnosing critical conditions. Furthermore, the Restful interface provides a simple way for sequencing tools to automatically retrieve binary compiled sequence SCMFs (Space Command Message Files) on demand. It also enables developers to change the underlying database, while maintaining the same interface to the existing applications. The logging capabilities are also beneficial to operators when they are trying to recall how they solved a similar problem many days ago: this software enables automatic recovery of SCMF and RML (Robot Markup Language) sequence files directly from the command EVRs, eliminating the need for people to find and validate the corresponding sequences. To address the lack of auditing capability for sequences onboard a spacecraft during earlier missions, extensive logging support was added on the Mars Science Laboratory (MSL) sequencing server. This server is responsible for generating all MSL binary SCMFs from RML input sequences. The sequencing server logs every SCMF it generates into a MySQL database, as well as the high-level RML file and dictionary name inputs used to create the SCMF. The SCMF is then indexed by a hash value that is automatically included in all command EVRs by the onboard flight software. Second, both the binary SCMF result and the RML input file can be retrieved simply by specifying the hash to a Restful web interface. This interface enables command line tools as well as large sophisticated programs to download the SCMF and RMLs on-demand from the database, enabling a vast array of tools to be built on top of it. One such command line tool can retrieve and display RML files, or annotate a list of EVRs by interleaving them with the original sequence commands. This software has been integrated with the MSL sequencing pipeline where it will serve sequences useful in diagnostics, debugging, and situational awareness throughout the mission
PosterVote:expanding the action repertoire for local political activism
Online and digital technologies support and extend the action repertoires of localized social movements. In this paper we examine the ways by which digital technologies can support ‘on-the-ground ’ activist communities in the development of social movements. After identifying some of the challenges of deploying conventional voting and consultation technologies for activism, we examine situated political action in local communities through the design and deployment of a low-cost community voting prototype, PosterVote. We deploy PosterVote in two case studies with two local community organizations identifying the features that supported or hindered grassroots democratic practices. Through interviews with these communities, we explore the design of situated voting systems to support grassroots democratic practices and participation within an ecology of social action. Author Keywords Democracy; activism; participation; e-votin
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