Italian Privileges and Trade in Byzantium before the Fourth Crusade: A Reconsideration

Between 1082 and· 1192 several Byzantine emperors conferred extensive privileges on the three main Italian maritime powers, Venice, Pisa and Genoa. A new reading of their commercial and fiscal provisions in a contemporary context and in a comparative framework reveals some misunderstood or overlooked aspects of their content, suggests novel inter­pretations, and sheds light on some of their effects on trade, shipping and the Italian settletment pattern in the Empire before the Fourth Crusade. The disparity between the respective privileges granted to the three maritime powers was far wider than generally assumed. Deliberate measures taken by the Byzantine government, the arbitrary action of its officials, especially in the provinces, and political developments affected in various ways, at times heavily, the implementation of these privileges and the benefit deri­ving from them. These factors should be taken into account in any evalua­tion of Italian trade and settlement in Byzantium and the impact these had on the Empire's economy.Divers empereurs byzantins octroyèrent de 1082 à 1192 des pri­vilèges étendus aux trois principales puissances maritimes italiennes, Venise, Pise et Gênes. Une nouvelle lecture des clauses commerciales et fiscales de ces privilèges dans un contexte contemporain et dans un cadre compara­tif révèle des aspects méconnus ou oubliés de leur contenu, suggère de nouvelles interprétations et éclaire certains de leurs effets sur le commerce, le transport maritime et l'implantation italienne dans l'Empire avant la qua­trième croisade. Les écarts entre les privilèges respectifs des trois puis­sances étaient beaucoup plus grands qu'on ne l'admet couramment. L'appli­cation de ces privilèges et le profit qui en dérivait ont été affectés de diver­ses manières, parfois sensiblement, par les mesures délibérées du gouverne­ment impérial, les actions arbitraires de ses officiers, en particulier dans les provinces, enfin, les développements politiques. Il faut tenir compte de ces facteurs dans toute évaluation du commerce et de l'implantation des Italiens dans l'Empire byzantin et de leur impact sur l'économie de celui-ci

Ariel - Volume 4 Number 1

Editors David A. Jacoby Eugenia Miller Tom Williams Associate Editors Paul Bialas Terry Burt Michael Leo Gail Tenikat Editor Emeritus and Business Manager Richard J. Bonnano Movie Editor Robert Breckenridg

Mentoring Urban African American Male Students in Secondary School

This narrative inquiry evaluated how a school-based mentorship program called The Chamber of Scholars: African American Male Mentoring Intervention, which served exclusively African American male students in high school, impacted the participants’ identification with academics, perception of mattering to their school, and academic performance. The program was evaluated using a pre-interview and a post-interview of all participants, daily field notes of activities, and weekly journals. The study found that participants who regularly attended daily intervention sessions for ten weeks increased their identification with academics (value of school). The study also found that participants who regularly attended daily intervention sessions for ten weeks perceived they mattered more to their school. Finally, the study found that participants who regularly attended daily intervention sessions for ten weeks improved their overall academic performance. The study also found that students who did not fully apply the lessons of the intervention did not improve their academic performance as significantly as those who did apply the lessons. The background for this narrative inquiry study came from the data that shows that African American male students are a low performing group of students in the United States school system, compared to other groups. The results of this are a resource for educational leaders who desire to design and implement subsequent school-based mentorship interventions for African American male students nationwide

A two-method solution to the investment timing option

Within the realm of derivative asset valuation, two types of methods are available for solving the investment timing option, each with a serious limitation for practical projects. Methods that use Monte Carlo simulation of risk-adjusted probability measures allow consideration of the complicated cash flow models typical of real projects, in the face of prespecified operating policies, but they do not provide an adequate way to determine what the optimal policy is. Formulation of the problem as an American option in the vein of Black-Scholes and Merton permits calculation of an optimal start policy, but only in situations with drastically simplified cash flow models. The solution to this dilemma is the development of an approach which applies the two methods in tandem. The rights to explore and develop an oil field are used as an example, and Monte Carlo simulation is used to calculate the value of these rights as a function of start time and contemporaneous oil price. This payoff function is then input to a Black-Scholes-Merton option calculation. The resulting optimal start policy is then reinserted to the Monte Carlo model for further analysis of project and individual cash-flow magnitudes and risks. Also, possible bias because of numerical-analysis errors are checked by direct search of start policies in the vicinity of the calculated optimum.Supported by the Social Science and Humanities Research Council of Canada, the Natural Science and Engineering Research Council of Canada, Imperial Oil and various research funds of the University of Alberta and the M.I.T. Center for Energy Policy Research

Short-term shocks, reversion, and long-term decision-making

Many observers claim that discounted cash-flow methods lead to a neglect of long-term and strategic decision-making. Using modern asset pricing methods, we examine one possible reason for this problem. If the cash-flows being discounted have an increasing dependence on an uncertain variable that tends to revert to a long-term equilibrium path in the face of short-term shocks, and if this reversion is ignored, then the uncertainty in the cash-flows will be overestimated. If this uncertainty causes risk discounting, then the amount of risk discounting that is appropriate will also be overestimated, which will tend to result in a relative undervaluation of long-term alternatives. We examine the implications of such an error for the comparative analysis of decision alternatives, including some involving an initial timing option. We use, as examples, decisions about production projects where the output price is the reverting variable.Where applicable, we look at two measures of what is meant by long-term: the operating duration of the project and the length of an initial timing option. For the projects without options, the analysis is based on the relatively straightforward "risk discounting effect" already mentioned. Reversion tends to decrease long-term uncertainty, and, with it, long-term risk discounting, which increases the relative value of long-term alternatives. Options complicate matters. The long-term decrease in uncertainty due to reversion tends directly to decrease long-term option values. Moreover, in addition to the original risk discounting effect and this "variance effect," there can be direct "future reversion effects" if the options involve a timing component or payoffs generated by cash-flows over a period of time. The overall influence can be a complicated mixture of the three different types of effects.We use this classification scheme to analyze two sets of examples: investment timing options on an instantaneous production project (equivalent to at-the-money American options on the project output price), and "now-or-never" options, as well as investment timing options, on projects that differ in their operating lives. We find that a neglect of reversion leads to an undervaluation of at- or in-the-money options on projects with longer operating lives. This is primarily due to the risk discounting effect. Longer timing options on the same project tend to be relatively overvalued by a neglect of reversion if the operating life of the project is moderately long, and undervalued if the project is instantaneous and currently at the money. The first is primarily due to variance and future-reversion effects. The second is primarily due to risk-discounting and future-reversion effects.Because parts of the economy may be influenced by short-term shocks in the presence of long-term equilibrium, these results suggest a reexamination of those aspects of analyses in the "real options" literature that depend on the use of non-reverting models.Supported by the Natural Science and Engineering Research Council of Canada, Imperial Oil University Research Grants, Interprovincial Pipeline Co., Saskoil, Exxon Corp., and the Social Science and Humanities Research Council of Canada, and by the Central Research Fund, a Nova Faculty Fellowship, the Muir Research Fund and the Institute for Financial Research of the University of Alberta, and by the Finance, Investment and Contracts Program of the MIT Center for Energy and Environmental Policy Research

Project evaluation : a practical asset pricing method

This paper presents a practical approach to project evaluation using techniques of modern financial economics, with a sample application to oil development under a complex tax system. The method overcomes shortcomings of conventional DCF methods which are either imprecise about the relation between economic value and uncertainty, or are rigid and unrealistic in the required assumptions about how a project's risks (and therefore its value) are influenced by market conditions, the project physical structure, and tax and contract provisions. It is based on the formulation and estimation of an "information model" which represents the resolution over time of uncertainties underlying a project (oil prices in the examples shown). Oil prices are the underlying uncertainty in the examples shown. The project can then be valued using derivative asset valuation, which replicates the consequences of a complex asset by a traded portfolio of simpler assets (in our case, riskless bonds and future claims on oil). For ease of implementation, the method is designed to resemble current industry practice. The information model can be estimated using analysis and judgment similar to that applied in conventional evaluation. The formulation of decision alternatives, the selection of underlying uncertainties, and the design of a cash-flow model are the same as in standard DCF methods. Simulation and valuation results also can be represented in a familiar format. Restrictions must be placed on the "best" current asset pricing theory to achieve this convenient framework: the expected returns on the basic assets, which comprise the portfolios traded to replicate project cash flows, must be assumed to be known with certainty at the time of an evaluation.Supported by the MIT Center for Energy Policy Research, the Social Science and Humanities Research Council of Canada, the Natural Science and Engineering Research Council of Canada, the Imperial Oil University Research Grants Programme, the Central Research Fund, a Nova Faculty Fellowship, the Muir Research Fund and the Institute for Financial Research of the University of Alberta

Ariel - Volume 3 Number 5

Editors Richard J. Bonanno Robin A. Edwards Associate Editors Steven Ager Tom Williams Lay-out Editor Eugenia Miller Contributing Editors Paul Bialas Robert Breckenridge Lynne Porter David Jacoby Terry Burt Mark Pearlman Michael Leo Mike LeWitt Editors Emeritus Delvyn C. Case., Jr. Paul M. Fernhof

A network analysis approach to understanding shark behaviour

The mechanisms and functions of shark grouping behaviour have received relatively little scientific attention to date. The current widespread use of social network analysis to study animal groups, in concert with rapid advances in animal tracking technology, now allows us to test specific hypotheses about how and why sharks form groups. This thesis uses replicated laboratory experiments to investigate some of the mechanisms underpinning aggregation in a model species of benthic, oviporous elasmobranch, the small spotted catshark (Scyliorhinus canicula L. 1758; Scyliorhinidae). Acoustic tracking of this species in the wild is also conducted to explore how network analyses can be adopted to study the localized movements, habitat connectivity and ranging behaviour of adult sharks. Groups of juvenile S. canicula were characterized by non-random social preferences, crucially, only when individuals were familiar with one another suggesting social recognition is important in young sharks of this species. Genetic analyses of parent and offspring DNA revealed very high levels of multiple paternity in this species, likely due to male sexual harassment and multiple mating, which leads to increased genetic diversity between juvenile sharks. Perhaps unsurprisingly, there was no evidence of kin relatedness structuring social interactions between conspecifics. Furthermore, testing the effects of environment on social behaviour provided evidence that these juveniles aggregated more in structurally complex environments than simple ones. However, at the individual level sharks showed consistency in their social network positions through time and across different habitat types. This result is indicative of personality traits in S. canicula. Using data gathered via passive acoustic telemetry of wild shark behaviour, network analysis provided a useful tool with which to quantify movement between receivers. One chapter has been dedicated to the application of these methods, highlighting a number of different analyses for predicting movement behaviour from such data. Finally, these methods were adopted to address ecological questions in this sexually segregated species. Persistent site fidelity to a localised inshore area by both male and female sharks suggested that segregation occurred at a relatively small spatial and temporal scale. Despite strong evidence of segregation, analyses of movement networks and individual co-occurrences revealed distinct periods of behavioural synchronicity during the months of March, April and May. In addition, habitat complexity appeared to be a significant driver of female behavioural strategy. Enhancing our knowledge of the social and environmental drivers of aggregation and movement in sharks is of great importance given the ecological threat facing many of our ocean’s top elasmobranch predators.Fisheries Society of the British Isle