The dynamic behavior of quota license prices : theory and evidence from the Hong Kong apparel quotas

Empirical studies of the welfare consequences of quotas often assume perfect competition everywhere. If this assumption is not valid, welfare estimate and policy recommendations may err dramatically. The popular press often argues that market power is being exercised in markets constrained by import quotas. The authors develop a framework for testing the hypothesis of perfect competition in the market for apparel quota licenses. Drawing on simple models, they predict the behavior of license prices, taking into account four influences on prices: scarcity value, option value, renewal value, and asset value. They explore the effect of imperfections in the license market on license price paths. They test allegations that there is price fixing in the market for Multi-Fibre Arrangement (MFA) apparel quota licenses in Hong Kong. (Hong Kong often serves as a benchmark case for the welfare consequences of the MFA.) They use monthly data on license prices and use rates to test for the presence of imperfect competition. They argue that a concentration of license holding could affect both the supply side and the demand side, by affecting the costs of search. These results accord well with the authors theoretical discussion, in which they point out that license use and price paths with imperfect competition in the license market may be quite different from the corresponding paths in the case of perfect competition - even though the total use of licenses is the same. The authors estimate the structural demand and supply equations of the model, which provide further evidence of imperfect competition in the license market. In particular, the intra-year path of quota license prices and of quota use are found to be affected by concentration in license holdings. The results, in short, suggest that market power exists in Hong Kong's quota license market. Hong Kong is often considered the prime example of perfect competition, so this has major implications for other developing countries.Environmental Economics&Policies,Industrial Management,Markets and Market Access,Access to Markets,Economic Theory&Research

Lightning testing at the subsystem level

Testing at the subsystem or black box level for lightning hardness is required if system hardness is to be assured at the system level. The often applied philosophy of lighting testing only at the system level leads to extensive end of the line design changes which result in excessive costs and time delays. In order to perform testing at the subsystem level two important factors must be defined to make the testing simulation meaningful. The first factor is the definition of the test stimulus appropriate to the subsystem level. Application of system level stimulations to the subsystem level usually leads to significant overdesign of the subsystem which is not necessary and may impair normal subsystem performance. The second factor is the availability of test equipment needed to provide the subsystem level lightning stimulation. Equipment for testing at this level should be portable or at least movable to enable efficient testing in a design laboratory environment. Large fixed test installations for system level tests are not readily available for use by the design engineers at the subsystem level and usually require special operating skills. The two factors, stimulation level and test equipment availability, must be evaluated together in order to produce a practical, workable test standard. The neglect or subordination of either factor will guarantee failure in generating the standard. It is not unusual to hear that test standards or specifications are waived because a specified stimulation level cannot be accomplished by in-house or independent test facilities. Determination of subsystem lightning simulation level requires a knowledge and evaluation of field coupling modes, peak and median levels of voltages and currents, bandwidths, and repetition rates. Practical limitations on test systems may require tradeoffs in lightning stimulation parameters in order to build practical test equipment. Peak power levels that can be generated at specified bandwidths with standard electrical components must be considered in the design and costing of the test system. Stimulation tests equipment and test methods are closely related and must be considered a test system for lightning simulation. A non-perfect specification that can be reliably and repeatedly applied at the subsystem test level is more desirable than a perfect specification that cannot be applied at all

Beyond Zipf's Law: The Lavalette Rank Function and its Properties

Although Zipf's law is widespread in natural and social data, one often encounters situations where one or both ends of the ranked data deviate from the power-law function. Previously we proposed the Beta rank function to improve the fitting of data which does not follow a perfect Zipf's law. Here we show that when the two parameters in the Beta rank function have the same value, the Lavalette rank function, the probability density function can be derived analytically. We also show both computationally and analytically that Lavalette distribution is approximately equal, though not identical, to the lognormal distribution. We illustrate the utility of Lavalette rank function in several datasets. We also address three analysis issues on the statistical testing of Lavalette fitting function, comparison between Zipf's law and lognormal distribution through Lavalette function, and comparison between lognormal distribution and Lavalette distribution.Comment: 15 pages, 4 figure

International Parities and Exchange Rate Determination

The model of equilibrium exchange rate combining purchasing power parity (PPP) and uncovered interest parity (UIP) is widely tested using the cointegration approach. Most of the recent studies, however, are deficient in the treatment of expectations and the power of tests. This paper aims at resolving the two deficiencies by deriving and testing the yen/dollar exchange rate model. Perfect foresight is assumed to circumvent the expectation problem and a modification of cointegration variables is introduced to improve the power of tests.Exchange rate; PPP; UIP

Improved Performance of Electric Transmission Concrete Poles for National Integrated Power Project (NIPP) in Nigeria

This paper deals with the testing of electric transmission concrete poles. The Dillon (precision Electronic Dynamometer family) used was inspected and was certified to be in perfect condition before testing commenced. 1000 concrete poles were tested arranged in batches of 400 and 300poles. These poles were arranged in such a manner that the markings, serial numbers e.t.c., with pole positions are easily seen. Also the poles were stacked in such a manner that any pole selected for testing was easily drawn out.  All poles tested satisfied the standard acceptance criteria to withstand any concrete pole failure for the National Integrated Power Project (NIPP) electrification purpose based on the experimental validations carried out for different actual applied loads plotted again the pole deflection. Keywords: NIPP, Concrete pole, testing, acceptance criteria, On-site assessmen

Multiple Testing and Variable Selection along Least Angle Regression's path

In this article, we investigate multiple testing and variable selection using Least Angle Regression (LARS) algorithm in high dimensions under the Gaussian noise assumption. LARS is known to produce a piecewise affine solutions path with change points referred to as knots of the LARS path. The cornerstone of the present work is the expression in closed form of the exact joint law of K-uplets of knots conditional on the variables selected by LARS, namely the so-called post-selection joint law of the LARS knots. Numerical experiments demonstrate the perfect fit of our finding. Our main contributions are three fold. First, we build testing procedures on variables entering the model along the LARS path in the general design case when the noise level can be unknown. This testing procedures are referred to as the Generalized t-Spacing tests (GtSt) and we prove that they have exact non-asymptotic level (i.e., Type I error is exactly controlled). In that way, we extend a work from (Taylor et al., 2014) where the Spacing test works for consecutive knots and known variance. Second, we introduce a new exact multiple false negatives test after model selection in the general design case when the noise level can be unknown. We prove that this testing procedure has exact non-asymptotic level for general design and unknown noise level. Last, we give an exact control of the false discovery rate (FDR) under orthogonal design assumption. Monte-Carlo simulations and a real data experiment are provided to illustrate our results in this case. Of independent interest, we introduce an equivalent formulation of LARS algorithm based on a recursive function.Comment: 62 pages; new: FDR control and power comparison between Knockoff, FCD, Slope and our proposed method; new: the introduction has been revised and now present a synthetic presentation of the main results. We believe that this introduction brings new insists compared to previous version

A framework for dialogue detection in movies

In this paper, we investigate a novel framework for dialogue detection that is based on indicator functions. An indicator function defines that a particular actor is present at each time instant. Two dialogue detection rules are developed and assessed. The first rule relies on the value of the cross-correlation function at zero time lag that is compared to a threshold. The second rule is based on the cross-power in a particular frequency band that is also compared to a threshold. Experiments are carried out in order to validate the feasibility of the aforementioned dialogue detection rules by using ground-truth indicator functions determined by human observers from six different movies. A total of 25 dialogue scenes and another 8 non-dialogue scenes are employed. The probabilities of false alarm and detection are estimated by cross-validation, where 70% of the available scenes are used to learn the thresholds employed in the dialogue detection rules and the remaining 30% of the scenes are used for testing. An almost perfect dialogue detection is reported for every distinct threshold. © Springer-Verlag Berlin Heidelberg 2006