Spatial Correlation Robust Inference with Errors in Location or Distance

This paper presents results from a Monte Carlo study concerning inference with spatially dependent data. We investigate the impact of location/distance measurement errors upon the accuracy of parametric and nonparametric estimators of asymptotic variances. Nonparametric estimators are quite robust to such errors, method of moments estimators perform surprisingly well, and MLE estimators are very poor. We also present and evaluate a specification test based on a parametric bootstrap that has good power properties for the types of measurement error we consider.

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

Pes Planus (Flat Feet) in Relation to Knee Pain

Pes Planus (Flat Foot) disorder has been found to be associated with frequent knee pain and medial tibiofemoral (TF) cartilage damage. The flattening of the foot causes this pain and damage within the knee by forcing the tibia to rotate internally increasing the rotational pressure on the TF joint. We will be discussing a few factors that may contribute to pes planus such as equines foot deformity, tibial torsion, tarsal coalition, ligamentous laxity and congenital vertical talus. Amongst some of these contributions, a reduction in physical activity at a young age can also be a root cause to flat feet and genu valgum (knock-knees). We also observed the types of rehabilitation techniques for improving pes planus. In order to control muscle skeletal discomfort, pain, and correct biomechanical processes, rehabilitation focuses on the muscles responsible for plantar flexion, dorsiflexion, pronation, and supination of the ankle. Controlling the lateral longitudinal arch stability of the ankle has also proven to be a reliable method of improving a flat foot. With the use of personalized orthotics and short foot exercises, improvements have been shown to be reached. These exercises are designed to strengthen and support the cross-sectional area of the foot containing the flexor halluces and abductor halluces muscles. Because pes planus is a problem in younger patients, it’s crucial to recognize the condition early and improve postural mechanics so arthritis and other joint damages can be prevented as the patient ages