Productivity and Resource Use Efficiency in Tomato and Watermelon Farms: Evidence from Ghana

This study examines productivity and resource use efficiency in tomato and watermelon farms in the Dangme East District of Ghana. Cross-sectional data of 200 farmers (100 tomato farmers and 100 watermelon farmers) were obtained from a field survey using structured questionnaires. The empirical results of this study show that, the value of output of watermelon is higher than that of tomato. The difference could be attributed to differences in output prices as well as labour and material input costs incurred in the production of each of these crops. Since prices of inputs are more or less stable over the season, output price difference could be said to be the main cause of this difference. For instance, it costs GH ¢704.59 to produce a hectare of tomato whereas the average cost of producing a hectare of watermelon is GH¢509.03. Conversely, a hectare of tomato yields GH¢480.37 whereas a hectare of watermelon yields GH¢1738.68. Analysis of the factors affecting the value of output of tomato and watermelon shows that, land, labour and experience exert significant influence on the value of output of tomato; whereas land, non-agricultural activity and training significantly influence the level of output of watermelon in the study area. Marginal value products computed for land and labour for each crop were found to be higher than the market prices of  these factors indicating that land and labour are inefficiently used in both tomato and watermelon production though labour did not significantly influence watermelon production. Also, neither did the amount of fertilizer used in tomato production nor the amount of capital used in watermelon production exert significant influence on their value of outputs; these inputs were found to be underutilized in each case. These results have implications for Agricultural policy in Ghana. Key Words: Productivity, Resource Use Efficiency, Tomato, Watermelon, Farms, Ghan

Sabotage in Contests: A Survey

A contest is a situation in which individuals expend irretrievable resources to win valuable prize(s). ‘Sabotage’ is a deliberate and costly act of damaging a rival’s' likelihood of winning the contest. Sabotage can be observed in, e.g., sports, war, promotion tournaments, political or marketing campaigns. In this article, we provide a model and various perspectives on such sabotage activities and review the economics literature analyzing the act of sabotage in contests. We discuss the theories and evidence highlighting the means of sabotage, why sabotage occurs, and the effects of sabotage on individual players and on overall welfare, along with possible mechanisms to reduce sabotage. We note that most sabotage activities are aimed at the ablest player, the possibility of sabotage reduces productive effort exerted by the players, and sabotage may lessen the effectiveness of public policies, such as affirmative action, or information revelation in contests. We discuss various policies that a designer may employ to counteract sabotage activities. We conclude by pointing out some areas of future research

Reduced evolutionary rate in reemerged Ebola virus transmission chains

On 29 June 2015, Liberia’s respite from Ebola virus disease (EVD) was interrupted for the second time by a renewed outbreak (“flare-up”) of seven confirmed cases. We demonstrate that, similar to the March 2015 flare-up associated with sexual transmission, this new flare-up was a reemergence of a Liberian transmission chain originating from a persistently infected source rather than a reintroduction from a reservoir or a neighboring country with active transmission. Although distinct, Ebola virus (EBOV) genomes from both flare-ups exhibit significantly low genetic divergence, indicating a reduced rate of EBOV evolution during persistent infection. Using this rate of change as a signature, we identified two additional EVD clusters that possibly arose from persistently infected sources. These findings highlight the risk of EVD flare-ups even after an outbreak is declared over