Speculative Attacks

Models with multiple equilibria are a popular way to explain currency attacks. Morris and Shin (1998) have shown that, in the context of those models, unique equilibria may prevail once noisy private information is introduced. In this paper, we generalize the results of Morris and Shin to a broader class of probability distributions and show - using the technique of iterated elimination of dominated strategies - that uniqueness will hold, even if we allow for sunspots and individual uncertainty about strategic behavior of other agents. We provide a clear exposition of the logic of this model and we analyse the impact of transparency on the probability of a speculative attack. For the case of uniform distribution of noisy signals, we show that increased transparency of government policy reduces the likelihood of attacks

Speculative attacks : unique sunspot equilibrium and transparency

Models with multiple equilibria are a popular way to explain currency attacks. Morris and Shin (1998) have shown that, in the context of those models, unique equilibria may prevail once noisy private information is introduced. In this paper, we generalize the results of Morris and Shin to a broader class of probability distributions and show - using the technique of iterated elimination of dominated strategies - that uniqueness will hold, even if we allow for sunspots and individual uncertainty about strategic behavior of other agents. We provide a clear exposition of the logic of this model and we analyse the impact of transparency on the probability of a speculative attack. For the case of uniform distribution of noisy signals, we show that increased transparency of government policy reduces the likelihood of attacks. JEL Classification F 31, D 82Modelle mit multiplen Gleichgewichten sind ein populärer Ansatz zur Erklärung spekulativer Attacken. Morris und Shin (1998) haben jedoch gezeigt, dass auch im Rahmen dieser Modelle eindeutige Gleichgewichte zu erwarten sind, sobald die Spekulanten verzerrte private Signale über die Fundamentaldaten erhalten. In dieser Arbeit verallgemeinern wir die Ergebnisse von Morris und Shin und zeigen, dass die Gleichgewichte selbst dann eindeutig sind, wenn Sunspot Variablen und individuelle Unsicherheit über Strategien zugelassen werden. Zudem analysieren wir, welchen Einfluss Transparenz auf die Wahrscheinlichkeit erfolgreicher Attacken hat. Für den Fall der Gleichverteilung verzerrter Signale zeigen wir, dass bei transparenter Geldpolitik ein Ausbruch solcher Attacken mit geringerer Wahrscheinlichkeit auftritt

The role of government in agricultural innovation: Lessons from Bolivia

"Many governments in developing countries attempt to foster agricultural development and innovation by setting up funding facilities, extension programs, and research centers and by subsidizing private-sector and farm activities through fiscal measures. However, when trying to manage complex innovation processes involving many and different actors, governments sometimes find it difficult to design effective interventions and therefore end up supporting and managing only the public research and extension organizations that directly depend upon them. With the aid of various donors, Bolivia introduced a scheme in 2001—the Bolivian Agricultural Technology System (SIBTA)—by which government support to agricultural research and extension was partly delegated to regional semiautonomous foundations. This brief presents the results of a study on the role of the Bolivian government in guiding and managing SIBTA. The study found that despite a number of weaknesses related to the design of the system and the government's limited commitment, the regional foundations have been able to effectively identify the demands of small farmers, set priorities, and provide transparency and accountability with regard to funding and decisionmaking. It suggests that instead of micromanaging such foundations, the government should focus on the big picture and conduct policy analysis and strategic planning to identify opportunities for agricultural innovation and set up incentive mechanisms and information networks that support the many actors involved in innovation processes." from textAgricultural innovations, Private sector, Technological innovations, Agricultural research, Agricultural development, stakeholders, Farmers, Producer organizations, Extension,

Upper Bound on the Capacity of a Cascade of Nonlinear and Noisy Channels

An upper bound on the capacity of a cascade of nonlinear and noisy channels is presented. The cascade mimics the split-step Fourier method for computing waveform propagation governed by the stochastic generalized nonlinear Schroedinger equation. It is shown that the spectral efficiency of the cascade is at most log(1+SNR), where SNR is the receiver signal-to-noise ratio. The results may be applied to optical fiber channels. However, the definition of bandwidth is subtle and leaves open interpretations of the bound. Some of these interpretations are discussed.Comment: The main change is to define the noise as bandlimited already in (8) rather than before (15). This serves to clarify subsequent step

Voronoi languages: Equilibria in cheap-talk games with high-dimensional types and few signals

We study a communication game of common interest in which the sender observes one of infinite types and sends one of finite messages which is interpreted by the receiver. In equilibrium there is no full separation but types are clustered into convex categories. We give a full characterization of the strict Nash equilibria of this game by representing these categories by Voronoi languages. As the strategy set is infinite static stability concepts for finite games such as ESS are no longer sufficient for Lyapunov stability in the replicator dynamics. We give examples of unstable strict Nash equilibria and stable inefficient Voronoi Languages. We derive efficient Voronoi languages with a large number of categories and numerically illustrate stability of some Voronoi languages with large message spaces and non-uniformly distributed types.Cheap Talk, Signaling Game, Communication Game, Dynamic stability, Voronoi tesselation

A Two-Dimensional Signal Space for Intensity-Modulated Channels

A two-dimensional signal space for intensity- modulated channels is presented. Modulation formats using this signal space are designed to maximize the minimum distance between signal points while satisfying average and peak power constraints. The uncoded, high-signal-to-noise ratio, power and spectral efficiencies are compared to those of the best known formats. The new formats are simpler than existing subcarrier formats, and are superior if the bandwidth is measured as 90% in-band power. Existing subcarrier formats are better if the bandwidth is measured as 99% in-band power.Comment: Submitted to IEEE Communications Letters, Feb. 201

Evidence that the Pomeron transforms as a non-conserved vector current

The detailed dependences of central meson production on the azimuthal angle phi, t and the meson J^P are shown to be consistent with the hypothesis that the soft Pomeron transforms as a non-conserved vector current. Further tests are proposed. This opens the way for a quantitative description of q-qbar and glueball production in p p -> p M p.Comment: 12 pages, latex, 4 figure