Social Networks in Ghana

In this chapter we examine social networks among farmers in a developing country. We use detailed data on economic activities and social interactions between people living in four study villages in Ghana. It is clear that economic development in this region is being shaped by the networks of information, capital and influence that permeate these communities. This chapter explores the determinants of these important economic networks. We first describe the patterns of information, capital, labor and land transaction connections that are apparent in these villages. We then discuss the interconnections between the various economic networks. We relate the functional economic networks to more fundamental social relationships between people in a reduced form analysis. Finally, we propose an equilibrium model of multi-dimensional network formation that can provide a foundation for further data collection and empirical research.Endogenous Networks, Informal Credit, Social Learning

Learning about a new technology: pineapple in Ghana

This paper investigates the role of social learning in the diffusion of a new agricultural technology in Ghana. We use unique data on farmers' communication patterns to define each individual's information neighborhood, the set of others from whom he might learn. Our empirical strategy is to test whether farmers adjust their inputs to align with those of their information neighbors who were surprisingly successful in previous periods. We present evidence that farmers adopt surprisingly successful neighbors' practices, conditional on many potentially confounding factors including common growing conditions, credit arrangements, clan membership, and religion. The relationship of these input adjustments to experience further supports their interpretation as resulting from social learning. In addition, we apply our methods to input choices for another crop with known technology and they correctly indicate an absence of social learning effects.

Learning About a New Technology: Pineapple in Ghana

This paper investigates the role of social learning in the diffusion of a new agricultural technology in Ghana. We use unique data on farmers’ communication patterns to define each individual’s information neighborhood, the set of others from whom he might learn. Our empirical strategy is to test whether farmers adjust their inputs to align with those of their information neighbors who were surprisingly successful in previous periods. We present evidence that farmers adopt surprisingly successful neighbors’ practices, conditional on many potentially confounding factors including common growing conditions, credit arrangements, clan membership, and religion. The relationship of these input adjustments to experience further supports their interpretation as resulting from social learning. In addition, we apply our methods to input choices for another crop with known technology and they correctly indicate an absence of social learning effects.Social Learning, Technology, Innovation

Nonrivalry and Price Discrimination in Copyright Economics

The literature on the economics of copyright proceeds from the premise that copyrightable works constitute pure public goods, which is generally modeled by assuming that such works are nonexcludable and that the marginal cost of making additional copies is essentially zero. A close examination of the foundational literature on public goods theory reveals that the defining characteristic of public goods is instead the optimality criterion known as the “Samuelson condition,” which implies that the systematic bias toward underproduction is the result of the inability to induce consumers to reveal their preferences rather than the inability to exclude or price at marginal cost. Reframing the analysis in terms of the Samuelson condition also contradicts the hostility toward price discrimination reflected in much of the literature by implying that price discrimination is a necessary condition for optimality. At the same time, it implies that the producer need only appropriate the marginal benefits created by the public good, which in turn provides a basis for determining an optimal level of price discrimination that still permits consumers to retain some of the surplus. Moreover, broadening public good models to reflect the fact that copyrighted works often serve as imperfect substitutes for one another allows the number of works to be determined endogenously. In such impure public goods models, the systematic bias toward underproduction disappears, and price discrimination once again may (but need not necessarily) promote optimality

Implementation of the StarT-Voyager bus interface units

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1997.Includes bibliographical references (p. 105-106).by Christopher Joseph Conley.M.S

Comparison And Validation Of Modelling Methods For Non-Homogenous Walls Incorporating Vacuum Insulation Panels

As of 2012, space heating accounted for 62% of Canada’s secondary residential energy use, the most significant category by a large margin. New strategies and policies to reduce overall energy consumption, with a focus on reducing space heating energy. Voluntary performances standards have been developed for new homes including R-2000, LEED Canada for Homes and Passive House. These standards add a series of performance criteria, in addition to conventional building code, in an effort to reduce a home’s energy consumption and include a limit on energy and water consumption, and prescribe minimum levels of insulation, ventilation, etc. Generally, extensive modelling, proof of concept and/or builder training are required to obtain the energy efficiency designation. A common method of maintaining a home within the constrained energy budget is to increase the overall air tightness and insulation in the dwelling above conventional construction standards through additional sealing and insulation. The typical industry practice for increasing the insulation value involves simply adding more insulation. However, this practice is not always possible or favorable. For example, adding thickness to the walls will either increase the dwelling’s footprint or reduce the usefulfloor space within the home. As a consequence, many studies are being performed on vacuum insulated panels (VIPs), which offer a high thermal resistance per unit thickness when compared to conventional materials. VIPs consist of a metallic enclosure and a vacuum maintained inside, effectively eliminating the conduction through the center of panel, however a thermal bridge will occur along the edges. There are concerns about whether the fragility and the non-homogenous nature of the panels will cause problems within residential dwellings, as well as how to model VIPs within building assemblies effectively. Currently, there is no method of efficiently modelling the non-homogenous nature of the panels in building applications to meet requirements prescribed in performance standards, hinders the widespread adoption of VIPs. This paper compares two methods of modelling the steady-state heat transfer across a composite, non-homogenous wall assembly containing VIPs validated against measured experimental data. Method 1 is the typical practice used by industry experts and involves creating a thermal model for each unique 2D profile within the wall assembly independently. The effective thermal conductivity (U-value) for the assembly was calculated using weighted averages method based on proportional coverage area of each profile and involves multiplying the U-value by the ratio of profile height to the overall height of the wall. In method 2, a single profile was created based on the wall composition, coverage area, and layout of non-homogenous sections to represent the entire assembly then modelled in THERM. The results of both methods were compared to an empirically calculated thermal resistance based on measured heat flux across five points in a representative assembly under steady-state conditions in a guarded hot box. The feasibility of using either modelling method to find the thermal resistance of wall assemblies incorporating VIPs and if a single representative profile can accurately determine thermal resistance to avoid modelling all profiles included within the wall was examined