A laboratory experiment in calculus for the high school

Thesis (M.A.)--Boston Universit

AN INSTRUMENTAL VARIABLES PANEL DATA APPROACH TO FARM SPECIFIC EFFICIENCY ESTIMATION

An instrumental variables panal data model was applied to a set of dairy farm financial and production records from the states of New York and Pennsylvania and the province of Quebec. This model allowed unbiased efficiency estimation without the drawbacks of a Fixed Effects specification.Industrial Organization, Livestock Production/Industries,

Capturing UK Real Estate Volitility

Volatility, or the variability of the underlying asset, is one of the key fundamental components of property derivative pricing and in the application of real option models in development analysis. There has been relatively little work on volatility in real terms of its application to property derivatives and the real options analysis. Most research on volatility stems from investment performance (Nathakumaran & Newell (1995), Brown & Matysiak 2000, Booth & Matysiak 2001). Historic standard deviation is often used as a proxy for volatility and there has been a reliance on indices, which are subject to valuation smoothing effects. Transaction prices are considered to be more volatile than the traditional standard deviations of appraisal based indices. This could lead, arguably, to inefficiencies and mis-pricing, particularly if it is also accepted that changes evolve randomly over time and where future volatility and not an ex-post measure is the key (Sing 1998). If history does not repeat, or provides an unreliable measure, then estimating model based (implied) volatility is an alternative approach (Patel & Sing 2000). This paper is the first of two that employ alternative approaches to calculating and capturing volatility in UK real estate for the purposes of applying the measure to derivative pricing and real option models. It draws on a uniquely constructed IPD/Gerald Eve transactions database, containing over 21,000 properties over the period 1983-2005. In this first paper the magnitude of historic amplification associated with asset returns by sector and geographic spread is looked at. In the subsequent paper the focus will be upon model based (implied) volatility.Real Estate, Volatility

AN ECONOMIC EVALUATION OF THE COLORADO RIVER BASIN SALINITY CONTROL PROGRAM

Dissolved salts (salinity) adversely affect numerous urban and agricultural users of Colorado River water in California and Arizona. Congress in 1974 authorized a major salinity control program. Studies of general economic benefits from salinity abatement and the cost per unit of salinity reduction expected from specific proposed projects have been developed by the responsible federal agencies, but no project-by-project evaluation has been published. We find a conceptual basis for a substantial downward revision of prospective economic benefits of salinity abatement. Revised benefits are compared with estimated costs, and only for five of the nineteen projects do economic benefits appear to exceed costs.Resource /Energy Economics and Policy,

Presence of a loner strain maintains cooperation and diversity in well-mixed bacterial communities

Cooperation and diversity abound in nature despite cooperators risking exploitation from defectors and superior competitors displacing weaker ones. Understanding the persistence of cooperation and diversity is therefore a major problem for evolutionary ecology, especially in the context of well-mixed populations, where the potential for exploitation and displacement is greatest. Here we demonstrate that a “loner effect”, described by economic game theorists, can maintain cooperation and diversity in real-world biological settings. We use mathematical models of public-good-producing bacteria to show that the presence of a loner strain, which produces an independent but relatively inefficient good, can lead to rock-paper-scissor dynamics, whereby cooperators outcompete loners, defectors outcompete cooperators, and loners outcompete defectors. These model predictions are supported by our observations of evolutionary dynamics in well-mixed experimental communities of the bacterium Pseudomonas aeruginosa. We find that the coexistence of cooperators and defectors, which respectively produce and exploit the iron-scavenging siderophore pyoverdine, is stabilized by the presence of loners with an independent iron-uptake mechanism. Our results establish the loner effect as a simple and general driver of cooperation and diversity in environments that 40 would otherwise favour defection and the erosion of diversity.Publisher PDFPeer reviewe

Translation Invariance and Finite Additivity in a Probability Measure on the Natural Numbers

Inspired by the two envelopes exchange paradox, a finitely additive probability measure m on the natural numbers is introduced. The measure is uniform in the sense that m ((i))=m ((j)) for all i, j∈□. The measure is shown to be translation invariant and has such desirable properties as m ((i∈□| i=0 (mod2)))=1/2. For any r∈ [0, 1], a set A is constructed such that m (A)=r; however, m is not defined on the power set of □. Finally, a resolution to the two envelopes exchange paradox is presented in terms of m

The Physico-Chemical Mechanism of Sea-Weed Drying

Drying of seaweed is desirable to reduce transport costs, to prevent decomposition and to permit easy compounding in feeding stuffs. Drying and grinding may be a preliminary stage in the extraction of algal chemicals. In all cases it is essential that drying is cheap and efficient, and this work is concerned with the investigation of this problem. The main seaweed studied was Laminaria cloustoni which is one of the commonest sublittoral species around British shores. L. digitata is also common and was compared with L. cloustoni: L. saccharina received less attention. The principal parts of these seaweeds are the stipe or stem containing 83-86% water and the fronds or blades with 75-90% water. A coating of mucilage on the fronds causes adhesion of cut pieces. The physical properties of these parts made it probable that dryers of the rotary-louvre, pneumatic and through-circulation types would be the most suitable for seaweed drying, and tests were made on each of these. It was shown that minced L. cloustoni stipe was readily dried in a rotary-louvre dryer, but that the sticky frond did not dry uniformly. A radioactive tracer technique was devised to measure the retention time of the frond in the dryer drum. A large-scale pneumatic dryer dealt easily with chopped stipe and whole plant, but again frond drying was unsatisfactory. A through-circulation grass dryer yielded a high quality dried seaweed meal from chopped frond. From these tests it was decided to make a detailed investigation of the drying characteristics of seaweed in a laboratory through-circulation dryer. The experimental procedure for cut stipe was established by preliminary tests on the effects of initial water content, interruption of drying and repeatability. The principal factors studied were: Bed depth, (0.5 - 7 in), Air temperature, (120 - 34