Novel applications of the NASA/GSFC Viterbi decoder hardware simulator

The NASA/GSFC developed an all digital, real time, programmable Viterbi decoder simulator operating at rates up to 6 Msps. With this simulator, the bit error rate (BER) performance of convolutionally encoded/Viterbi decoded Shuttle-TDRSS return link channels under pulsed radio frequency interference (RFI) conditions has been predicted. The principles of the simulator are described with special emphasis on the channel simulator and the essential interaction between CLASS software and the simulator. The sensitivity of coded BER as function of several illustrative RFI parameters is discussed for two typical Shuttle-TDRSS return link configurations

IS-LM and Monetarism

This paper discusses monetarist objections to the IS-LM model. We explore the views of two principal spokesmen for monetarism: Milton Friedman and the team of Karl Brunner and Allan Meltzer. Friedman did not explicitly state the reasons he generally chose not to use the IS-LM model in rejecting Keynesian views on the demand function for money, the role of autonomous expenditures in cyclical fluctuations, the potency of fiscal policy as against monetary policy, etc. He presented statistical findings, historical evidence, and econometric results to support his alternative analysis of macroeconomics, but his critics were unconvinced. In 1970, in an effort to use his critics' common language, he set up a model with explicit terms for IS-LM to encompass both the quantity theory and the income-expenditure theory. Friedman attributed the failure of this effort to the fact that he was a Marshallian, his opponents Walrasians. Brunner and Meltzer's objections to IS-LM were explicit. They found it too spare, so they elaborated it by adding a credit market, disaggregating the asset market by specifying three assets: base money, government debt, and real capital. They set up a model with financial institutions and utilized it to study the effects of a variety of policies. In brief, summarizing the views of both Friedman and Brunner and Meltzer, monetarists dislike the IS-LM framework because it limits monetary influence too narrowly, essentially to the interest elasticity of money demand, and defines investment in an excessively narrow fashion, and even that is not explicit.

The Specie Standard as a Contingent Rule: Some Evidence for Core and Peripheral Countries, 1880-1990

The specie standard that prevailed before 1914 was a contingent rule. Under the rule specie convertibiltity could be suspended in the event of a well understood, exogenously produced emergency, such as a war, on the understanding that after the emergency had safely passed convertibility would be restored at the original parity. Market agents would regard successful adherence as evidence of a credible commitment and would allow th authorities access to seignorage and bond finance at favorable terms. This paper surveys the history of the specie standard as a contingent rule for 21 countries divided into core and peripheral countries. As a comparison we also briedfly consider the Bretton Woods system and the recent managed floating regime. We then present evidence across four regimes (pre-1914 gold standard; interward gold standard; Bretton Woods; the subsequent managed exchange rate float) for the 21 countries on the stability of macro variables as well as on the demand shocks (reflecting policy actions specific to the regime) and supply shocks (reflecting shocks to the environment independence of the regime). These measures allow us to determine whether adherents to the rule consistently pursued different policy actions from nonadherents, and whether persistent adverse shocks to the environment may, for some countries, have precluded adherence to the rule.

Charles Goodhart's Contributions to the History of Monetary Institutions

Our paper examines Charles Goodhart's work on the history of monetary institutions: central bank operations under the gold standard, their behaviour in relation to the financial system in which they functioned, including their responses to banking crises, and their performance as lenders of last resort. Although we differ with Charles on some of the conclusions that he has reached, we pay tribute to his importance in shaping the discussion by economists over a thirty-year span on questions related to the functioning of banks, their customers, and the historic central banks that evolved from serving government to serving banks.

Monetary economic research at the St. Louis Fed during Ted Balbach's tenure as research director

Ted Balbach served as research director at the Federal Reserve Bank of St. Louis from 1975 to 1992. This paper lauds his contributions during that time, including the expanded influence of the Review, enhanced databases and data publications, and a visiting scholar program that attracted leading economists from around the world. Balbach is remembered fondly as a visionary leader and gracious mentor.Balbach, Anatol ; Federal Reserve Bank of St. Louis ; Research

Measuring Real Economic Effects of Bailouts: Historical Perspectives on How Countries in Financial Distress Have Fared With and Without Bailouts

In this paper we first trace the changing nature of banking, currency and debt crises from the last century to the present. Each type of crisis has transmogrified in the presence of official intervention and the creation of a safety net. A similar pattern is observed for international rescue loans. We then present evidence suggesting that the incidence has increased and the severity of financial crises has changed little in emerging markets from the pre-1914 era to the present. Finally we assess the impact of IMF loans on the macro performance of the recipients. A simple with-without comparison of countries receiving IMF assistance during crises in the period 1973-98 with countries in the same region not receiving assistance suggests that the real performance of the former group was possibly worse than the latter. Similar results obtain adjusting for self-selection bias and counterfactual policies.

The ECU - An Imaginary or Embryonic Form of Money: What Can We Learn from History?

We present historical examples of new forms of money that can be com- pared with the ECU. We first define the ECU in its official role before turning to developments in the private market for ECUs. We then examine historical antecedents of three attributes of ECUs: a unit of account; a basket of currencies; a basis for monetary integration. We discuss which features if any of ECUs are unique, and the contribution of the historical analysis to assessing the future of ECUs. We then ask whether governments or markets have been dominant in the emergence of new forms of money. Whatever emerges as money in an economy becomes the general means of payment. Prices of commodities, services, and bonds are expressed in units of the money. Buyers use the money to purchase goods or bonds and sellers receive the money is exchange for goods or bonds. We conclude that, at this stage in its history, the ECU at best is an embryonic form of money, closer to historical imaginary monies than to existing currencies that the world has known.

1-loop matching and NNLL resummation for all partonic 2 to 2 processes in QCD

The Wilson Coefficients for all 4-parton operators which arise in matching QCD to Soft-Collinear Effective Theory (SCET) are computed at 1-loop. Any dijet observable calculated in SCET beyond leading order will require these results. The Wilson coefficients are separated by spin and color, although most applications will involve only the spin-averaged hard functions. The anomalous dimensions for the Wilson coefficients are given to 2-loop order, and the renormalization group equations are solved explicitly. This will allow for analytical resummation of dijet observables to next-to-next-to-leading logarithmic accuracy. For each channel, there is a natural basis in which the evolution is diagonal in color space. The same basis also diagonalizes the color evolution for the soft function. Even though soft functions required for SCET calculations are observable dependent, it is shown that their renormalization group evolution is almost completely determined by a universal structure. With these results, it will be possible to calculate hadronic event shapes or other dijet observables to next-to-leading order with next-to-next-to-leading log resummation.Comment: 28 pages, 5 tables; v2: typo corrected in Eq. (56

Dynamical Inequality in Growth Models

A recent exponent inequality is applied to a number of dynamical growth models. Many of the known exponents for models such as the Kardar-Parisi-Zhang (KPZ) equation are shown to be consistent with the inequality. In some cases, such as the Molecular Beam Equation, the situation is more interesting, where the exponents saturate the inequality. As the acid test for the relative strength of four popular approximation schemes we apply the inequality to the exponents obtained for two Non Local KPZ systems. We find that all methods but one, the Self Consistent Expansion, violate the inequality in some regions of parameter space. To further demonstrate the usefulness of the inequality, we apply it to a specific model, which belongs to a family of models in which the inequality becomes an equality. We thus show that the inequality can easily yield results, which otherwise have to rely either on approximations or general beliefs.Comment: 6 pages, 4 figure