The Structural Estimation of Principal-Agent Models by Least Squares: Evidence from Land Tenancy in Madagascar

We develop a method to structurally estimate principal-agent models by ordinary least squares (OLS). We set up a general principal-agent model which explicitly incorporates the wealth levels of each party and the opportunity cost to the agent of entering the contract. This yields an optimal contract that is linearized by way of an Nth order Taylor approximation. This in turn imposes N(3N-1)/2 restrictions on the parameters and yields an empirical test of the canonical principal-agent model. In the application, we consider the case where N = 2 and apply our method to a sample of land tenancy contracts in rural Madagascar. Empirical tests lead to consistent failure to reject the hypotheses derived from our structural model, which lends support to our structural method as well as to the canonical principal-agent model.Principal-Agent Models, Contract Theory, Structural Estimations, Risk and Uncertainty, C12, C13, D86, O12, Q12,

Traditional Biocidal Replacement Viability of Microcrystalline Silver Chloride

The antimicrobial effects of silver ions and silver chloride nanoparticles have been well established while the efficacy of microcrystalline silver chloride has been less studied. Certex-AM, a microcrystalline silver chloride product produced by Cerion, Rochester, NY, was tested for its antimicrobial properties as a possible replacement for traditional biocidal techniques used in water cooling towers. The minimum inhibitory concentration (MIC) of the compound was determined using a microtiter broth assay. The compound was found to have inhibitory effects on bacterial growth for all tested organisms at concentrations greater than 9 ppm. Additional testing simulating a water cooling system showed the effectiveness of reducing an established wild population at concentrations of 10 ppm of the microcrystalline silver chloride. Certex-AM was found to be a promising replacement for traditional biocides as well as for other applications. Introduction of effective antimicrobial compounds such as this could reduce the pathogenic risk to humans associated with water cooling towers

Advanced Oxidation of Drinking Water using Ultraviolet Light and Alternative Solid Forms of Hydrogen Peroxide

With the increasing focus on removing emerging, unregulated drinking water contaminants, the use of advanced oxidation processes (AOPs) has become more prevalent. A commonly used AOP is the ultraviolet light/hydrogen peroxide (UV/H2O2) AOP. This process utilizes the formation of hydroxyl radicals to oxidize contaminants to less harmful forms. In this analysis, two alternative solid forms of H2O2, sodium perborate (SPB) and sodium percarbonate (SPC) were used as sources of H2O2 in the UV/H2O2 AOP. The potential advantage of SPB and SPC is that they are solids in nature, and as a result, the shipping costs and shipping energy requirements can be reduced significantly compared to that of liquid H2O2. The yields of active H2O2 via SPB and SPC were investigated in deionized (DI) water and three natural water sources from the Northampton, MA Water Filtration Plant. In DI water, the active yields of H2O2 via SPB and SPC were much higher than in the vii natural water sources. The findings of this analysis indicate that both SPB and SPC are viable sources of H2O2, especially in waters that are treated to reduce the background carbonate concentration. In highly finished waters similar to DI water, it is expected that the use of SPB and SPC will result in reduced oxidation rates of drinking water contaminants. Therefore, the use of SPB and SPC as H2O2 sources in the UV/H2O2 AOP in highly finished waters is not encouraged. In natural water sources, SPB and SPC appear to be viable alternatives to liquid H2O2 for use in the UV/H2O2 AOP up to active H2O2 concentrations of 5mg/L. Using SPB and SPC has the potential for significant cost savings depending on the source of the water used in the drinking water treatment process. For facilities with surface waters as the source water, significant cost savings are possible. However water reclamation and reuse facilities have high purity source waters and SPB and SPC as sources of H2O2 are more costly alternatives. The reduction in treatment facilities carbon footprints‟ associated with shipping H2O2 is largely dependent on the location of the chemical production facilities of each reagent

Black Dragon

In Black Dragon, Zachary F. Price illuminates martial arts as a site of knowledge exchange between Black, Asian, and Asian American people and cultures to offer new insights into the relationships among these groups. Drawing on case studies that include Kareem Abdul-Jabbar’s appearance in Bruce Lee’s film Game of Death, Ron Van Clief and the Black Panther Party for Self-Defense, the Wu-Tang Clan, and Chinese American saxophonist Fred Ho, Price argues that the regular blending and borrowing between these distinct cultural heritages is healing rather than appropriative. His analyses of performance, power, and identity within this cultural fusion demonstrate how, historically, urban working-class Black men have developed community and practiced self-care through the contested adoption of Asian martial arts practice. By zeroing in on this rich but heretofore understudied vein of American cultural exchange, Price not only broadens the scholarship around sites of empowerment via such exchanges but also offers a compelling example of nonessentialist liberation for the twenty-first century