Muslim World in British Fictions of the Nineteenth Century

British Academ

THE VALUE ADDED TAX: A PRELIMINARY LOOK AT EFFECTS ON THE AGRICULTURAL SECTOR

Public Economics,

The Differential Scheme and Quantum Computation

It is well-known that standard models of computation are representable as simple dynamical systems that evolve in discrete time, and that systems that evolve in continuous time are often representable by dynamical systems governed by ordinary differential equations. In many applications, e.g., molecular networks and hybrid Fermi-Pasta-Ulam systems, one must work with dynamical systems comprising both discrete and continuous components. Reasoning about and verifying the properties of the evolving state of such systems is currently a piecemeal affair that depends on the nature of major components of a system: e.g., discrete vs. continuous components of state, discrete vs. continuous time, local vs. distributed clocks, classical vs. quantum states and state evolution. We present the Differential Scheme as a unifying framework for reasoning about and verifying the properties of the evolving state of a system, whether the system in question evolves in discrete time, as for standard models of computation, or continuous time, or a combination of both. We show how instances of the differential scheme can accommodate classical computation. We also generalize a relatively new model of quantum computation, the quantum cellular automaton, with an eye towards extending the differential scheme to accommodate quantum computation and hybrid classical/quantum computation. All the components of a specific instance of the differential scheme are Convergence Spaces. Convergence spaces generalize notions of continuity and convergence. The category of convergence spaces, Conv, subsumes both simple discrete structures (e.g., digraphs), and complex continuous structures (e.g., topological spaces, domains, and the standard fields of analysis: R and C). We present novel uses for convergence spaces, and extend their theory by defining differential calculi on Conv. It is to the use of convergence spaces that the differential scheme owes its generality and flexibility

The Adequacy of Speculation in Agricultural Futures Markets: Too Much of a Good Thing?

The objective of this report is to re-visit the “adequacy of speculation” debate in agricultural futures markets. The Commodity Futures Trading Commission makes available the positions held by index funds and other large traders in their Commitment of Traders reports. The results suggest that after an initial surge from early 2004 through mid-2005, index fund positions have stabilized as a percent of total open interest. Traditional speculative measures do not show any material changes or shifts over the sample period. In most markets, the increase in long speculative positions was equaled or surpassed by an increase in short hedging. So, even after adjusting speculative indices for index fund positions, values are within the historical ranges reported in prior research. One implication is that long-only index funds may be beneficial in markets traditionally dominated by short hedging. Attempts to curb speculation through regulatory means should be weighed carefully against the potential benefits provided by this class of speculators.Commitment’s of Traders, index funds, commodity futures markets, Agricultural Finance, Financial Economics,

A Speculative Bubble in Commodity Futures Prices? Cross-Sectional Evidence

Recent accusations against speculators in general and long-only commodity index funds in particular, include: increasing market volatility, distorting historical price relationships, and fueling a rapid increase and decrease in commodity inflation. Some researchers have argued that these market participants—through their impact on market prices—may inadvertently prevented the efficient distribution of food aid to deserving groups. Certainly, this result—if substantiated— would counter the classical argument that speculators make prices more efficient and thus improve the economic efficiency of the agricultural and food marketing system. Given the very important policy implications, it is crucial to develop a more thorough understanding of long-only index funds and their potential market impact. Here, we review the criticisms (and rebuttals) levied against (and for) commodity index funds in recent U.S. Congressional testimonies. Then, additional empirical evidence is added regarding cross-sectional market returns and the relative levels of long-only index fund participation in 12 commodity futures markets. The results suggest that index fund positions across futures markets have no impact on relative price changes across those markets. The empirical results provide no evidence that long-only index funds impact commodity futures prices.Commitment’s of Traders, index funds, commodity futures markets, Agribusiness, Agricultural Finance, Farm Management, Financial Economics, Research Methods/ Statistical Methods, Risk and Uncertainty,