Mechanical properties of plastics predetermined by empirical method

To predetermine the mechanical properties of rigid plastics as a function of plasticizer content and composition, a set of equations has been empirically derived. These relate strain rate, yield stress, temperature, and weight fraction of the plasticizer

Testing Nonlinear Logit Models of Performance Effectiveness Ratings: Cooperative Extension and Organic Farmers

Survey evidence from U.S. organic farmers is evaluated to identify the factors influencing effectiveness ratings of cooperative extension advisors by organic farmers. A nonlinear logit model is specified for the ratings provided by organic producers, and critical demographic and management factors that influence the ratings are identified. The impact of the organic farmers’ status in transitioning to organic production is highlighted. The results indicate that part-time, newer adopters of organic farming methods are more likely to rate extension service providers as effective providers of information. Scenarios to predict extension effectiveness when interacting with specific groups of organic farmers are developed.cooperative extension, nonlinear logit model, organic farming, performance ratings, Agribusiness, Farm Management, Productivity Analysis, C25, Q16, Q01,

Assessing the Technical and Allocative Efficiency of Marketing Decisions by U.S. Organic Producers

We develop measures of technical and allocative efficiency of producers in marketing certified organic products. A stochastic output distance frontier and the associated revenue share equations are estimated using comprehensive U.S. data on certified organic producers. Farm-level measures of technical efficiency are calculated and factors which enhance performance are identified. Factors that systematically influence allocative efficiency are assessed. The revenue mix of organic producers is systematically inefficient as both male and female producers rely too heavily on revenue from organic markets relative to conventional outlets.organic farming, stochastic frontier, technical efficiency, allocative efficiency, Farm Management, Marketing, D21, C31, Q01,

CERTIFICATION AND SUPPLY RESPONSE IN THE ORGANIC LETTUCE MARKET

The impact of supply relationships and certification programs on the organic lettuce market is examined using an integrated partial adjustment and asymmetric supply response model. Costs associated with organic certification, production, and marketing have not restricted producersÂ’' abilities to respond to price signals. Organic growers allocate output between certified and noncertified markets in response to changing price premiums. Estimates of short-run supply elasticities indicate that organic lettuce growers are more responsive to price changes than producers of nonorganic lettuce. Long-run elasticity has increased since 1988, a change that coincides with the market entry of larger producers.Crop Production/Industries, Industrial Organization,

ORGANIC PEST MANAGEMENT DECISIONS: A SYSTEMS APPROACH

Organic farmers make system-level crop protection decisions that combine complementary insect, disease, nematode, and weed management strategies. Data from a national survey of U.S. organic farmers were used in a multivariate count data model to identify the farm and regional factors influencing adoption across the linked pest management categories. The results showed that weed management requires the greatest management effort by organic farmers. More intensive information-seeking and on-farm experimentation, higher educational attainment, and intensity of commitment to organic farming were positively related to the number of weed control strategies adopted. Predictions of adoption based on this model and customized to farm and region specifications will give information providers lead time to develop technical support for reduced chemical pest management systems.Crop Production/Industries,

Improving Extension Effectiveness for Organic Clients: Current Status and Future Directions

Responses from a national survey of U.S. organic farmers indicated dissatisfaction with the extension service. An ordered probit model was used to identify the factors influencing effectiveness ratings of extension advisors by farmers. Study findings show that part-time, higher income organic farmers who used a variety of highly rated private-sector information sources rated extension providers as more effective. Farmers in the Northeast and West regions rated extension usefulness more highly than in other regions. Not accounting for these demographic components in effectiveness ratings may result in under- or overestimation of results of organic-targeted extension programs. Extension agents can improve their usefulness to organic farmers by complementing educational and technical services offered by the private sector, and by facilitating farmer information exchanges as well as presenting relevant research findings as they have traditionally done.extension service, ordered probit model, organic farming, Teaching/Communication/Extension/Profession,

The Influence of Local Selling Decisions on Organic Farm Incomes

Abstract: This paper examines the factors that influence earned income of organic farmers given their decisions to engage in local selling. The model explicitly accounts for the sorting of producers across different levels of commitment to local sales on the basis of both observable and unobservable heterogeneity. The significant selectivity coefficients confirm that when producers choose to market organic products primarily through local outlets, earnings are overestimated (biased upward) if the selectivity corrections are neglected. Positive selection effects are present for farmers most intensively involved in local sales, contributing to higher earnings on average for these producers.organic marketing, local food, selectivity bias, ordered probit, Agribusiness, Marketing, L25, L81, J24,

MANAGEMENT STRATEGIES AND HUMAN CAPITAL INVESTMENTS BY ORGANIC PRODUCERS

Survey evidence from U.S. organic farmers is evaluated to identify the factors influencing adoption of farm management strategies to mitigate the impact of key production constraints. A multilevel count data model is specified for the number of frequently used management strategies adopted by organic farmers facing pest control problems.Farm Management, Labor and Human Capital,