Effects of Antidumping Duties with Bertrand Competition: Some Evidence for Frozen Catfish Fillets

Antidumping duties are popular in the United States because under the Byrd Amendment domestic industry gets to keep tariff revenues. However, whether antidumping duties are an effective instrument of protection depends crucially on the tariff's ability to increase demand for the home good. Under Bertrand competition, the Byrd Amendment enhances tariff effects on the home price and trade flows in comparison to perfect competition. Assuming Bertrand competition and differentiated products, price-reaction functions of frozen catfish fillets are derived and estimated jointly with a demand equation using monthly data for the period January 1999 - December 2005. An inverse demand equation for farm-level products is also added to explore the efficacy of the tariff on price of farmed catfish. The estimated increase associated with the duty is exhibited tiny in price and sales of domestic fillets but insignificant in farm price. The result suggests antidumping duties are a weak tool for protecting the domestic catfish industry.antidumping tariff, Bertrand competition, Byrd Amendment, catfish, price, International Relations/Trade, Resource /Energy Economics and Policy,

Unexpected Outcomes during the Attempted Iodination of Biphenol

The goal of this research was to create a new procedure to iodinate 4,4- biphenol using a ball miller. Iodination of 4,4-biphenol was first attempted in solution using electrophilic aromatic substitution. Several attempts were made to iodinate 4,4-biphenol, but the general insolubility of crude products inhibited progress. Interestingly, NMR analysis of the aqueous ammonia product suggested that 4,4-biphenol dimerized or polymerized with itself to make an ether. The exact mechanism by which the ether dimer was created is unknown, but the reaction may have occurred using a radical mechanism. Though the original goal of the project is left unmet, a future inquiry into the ether dimer could prove just as fascinating

A Rate-Distortion Exponent Approach to Multiple Decoding Attempts for Reed-Solomon Codes

Algorithms based on multiple decoding attempts of Reed-Solomon (RS) codes have recently attracted new attention. Choosing decoding candidates based on rate-distortion (R-D) theory, as proposed previously by the authors, currently provides the best performance-versus-complexity trade-off. In this paper, an analysis based on the rate-distortion exponent (RDE) is used to directly minimize the exponential decay rate of the error probability. This enables rigorous bounds on the error probability for finite-length RS codes and leads to modest performance gains. As a byproduct, a numerical method is derived that computes the rate-distortion exponent for independent non-identical sources. Analytical results are given for errors/erasures decoding.Comment: accepted for presentation at 2010 IEEE International Symposium on Information Theory (ISIT 2010), Austin TX, US

On Multiple Decoding Attempts for Reed-Solomon Codes: A Rate-Distortion Approach

One popular approach to soft-decision decoding of Reed-Solomon (RS) codes is based on using multiple trials of a simple RS decoding algorithm in combination with erasing or flipping a set of symbols or bits in each trial. This paper presents a framework based on rate-distortion (RD) theory to analyze these multiple-decoding algorithms. By defining an appropriate distortion measure between an error pattern and an erasure pattern, the successful decoding condition, for a single errors-and-erasures decoding trial, becomes equivalent to distortion being less than a fixed threshold. Finding the best set of erasure patterns also turns into a covering problem which can be solved asymptotically by rate-distortion theory. Thus, the proposed approach can be used to understand the asymptotic performance-versus-complexity trade-off of multiple errors-and-erasures decoding of RS codes. This initial result is also extended a few directions. The rate-distortion exponent (RDE) is computed to give more precise results for moderate blocklengths. Multiple trials of algebraic soft-decision (ASD) decoding are analyzed using this framework. Analytical and numerical computations of the RD and RDE functions are also presented. Finally, simulation results show that sets of erasure patterns designed using the proposed methods outperform other algorithms with the same number of decoding trials.Comment: to appear in the IEEE Transactions on Information Theory (Special Issue on Facets of Coding Theory: from Algorithms to Networks

A Simple Proof of Maxwell Saturation for Coupled Scalar Recursions

Low-density parity-check (LDPC) convolutional codes (or spatially-coupled codes) were recently shown to approach capacity on the binary erasure channel (BEC) and binary-input memoryless symmetric channels. The mechanism behind this spectacular performance is now called threshold saturation via spatial coupling. This new phenomenon is characterized by the belief-propagation threshold of the spatially-coupled ensemble increasing to an intrinsic noise threshold defined by the uncoupled system. In this paper, we present a simple proof of threshold saturation that applies to a wide class of coupled scalar recursions. Our approach is based on constructing potential functions for both the coupled and uncoupled recursions. Our results actually show that the fixed point of the coupled recursion is essentially determined by the minimum of the uncoupled potential function and we refer to this phenomenon as Maxwell saturation. A variety of examples are considered including the density-evolution equations for: irregular LDPC codes on the BEC, irregular low-density generator matrix codes on the BEC, a class of generalized LDPC codes with BCH component codes, the joint iterative decoding of LDPC codes on intersymbol-interference channels with erasure noise, and the compressed sensing of random vectors with i.i.d. components.Comment: This article is an extended journal version of arXiv:1204.5703 and has now been accepted to the IEEE Transactions on Information Theory. This version adds additional explanation for some details and also corrects a number of small typo