一种级联两箱通用数字预失真器及其辨识算法

提出了一种由单形规范线性分段(SCPWL)函数与记忆多项式级联的数字预失真器，并给出了复数域两步最小二乘参数辨识算法。不同于以往一种预失真器适用一种功放模型的情况，所提的预失真算法利用SCPWL函数的分段特性以及记忆多项式的非线性记忆特性，在完成参数辨识的同时自动地调整结构，可适用于传统以及强非线性新型功放模型的线性化补偿。将所提预失真器分别应用于传统记忆多项式、两箱模型以及新型包络跟踪功放。经过计算机仿真，功放输出的幅频特性和频谱曲线表明所提预失真器能够有效地补偿多种功放的非线性特性。算法仿真比较结果也表明，针对包络跟踪功放，所提复数两步最小二乘算法的邻道泄漏比(ACLR)可改善约35 dB，性能优于最小均方(LMS)类算法约30 dB。     

Carbon tax simulations using a household demand model

The main objective of this paper is to analyse consumer response and welfare effects due to changes in energy or environmental policy. To achieve this objective we formulate and estimate an econometric model for non-durable consumer demand in Sweden that utilises micro- and macro-data. In the simulations, we consider two revenue neutral scenarios that both imply a doubling of the CO₂ tax; one that returns the revenues in the form of a lower VAT and one that subsidise public transport. One conclusion from the simulations is that the CO₂ tax has regional distribution effects, in the sense that household living in sparsely populated areas carry a larger share of the tax burden.     

Cities under stress

This paper studies the effect of terrorist attacks on the internal structure of cities. We develop an urban framework with capital structures suitable for the study of this question and analyze the long and short term implications of this type of events. In the long run, the analysis shows that a terrorist attack will affect urban structure only modestly, relative to the potentially large decrease in the level of economic activity in the city. Land rents will not decline at all locations. In the short run, agglomeration forces will amplify the effect of the original destruction and will reduce urban economic activity temporarily.     

Entry and growth in a perfectly competitive vintage model

A perfectly competitive vintage-knowledge model of Schumpeterian growth is introduced to study the relation between growth, technology-lifetime, entry, and productivity-dispersion. The incentive to innovate is generated by the productivity-dispersion (latent in traditional vintage models) between new and old plants, rather than by monopoly rents. The model has a unique steady-state REE with endogenous growth. The endogenous extent of entry constitutes a buffer, dampening the effect of research-efficiency and completely neutralizing the effect of population size or population growth rates on per-capita income levels and growth rates. Variations of research-efficiency lead to a negative relation between growth and vintage-lifetime and a non-monotonic relation between growth and productivity-dispersion.     

Equity‐Based Compensation for Employees: Firm Performance and Determinants

I examine the effect of employee equity‐based compensation (EBC) on firm performance and the determinants of EBC. Using two samples, I find that firms have come to rely more heavily on EBC than in the past. For both samples, I document a significant, positive relation between Tobin's q and the percentage of employee compensation that is equity based. For accounting returns, I find a positive relation with the earlier sample. However, for the later sample I find that greater use of EBC leads to lower levels of future accounting returns. I also find that the determinants of the proportion of EBC are different between the two samples.     

三线铁路荷载作用下箱梁桥荷载横向分布系数

文章运用有限元程序对三线铁路预应力混凝土连续箱梁桥进行了模拟,分析了三线铁路荷载作用下箱梁的受力特性及在各种荷载工况下荷载横向分布规律,给出了荷载横向系数的实用值。     

The Impact of Regulation Fair Disclosure on Information Asymmetry and Trading: An Intraday Analysis

This study examines the impact of Regulation Fair Disclosure (FD) on liquidity, information asymmetry, and institutional and retail investors trading behavior. Our main findings suggest three conclusions. First, Regulation FD has been effective in improving liquidity and in decreasing the level of information asymmetry. Second, retail trading activity increases dramatically after earnings announcements but there is a significant decline in institutional trading surrounding earnings announcements, particularly in the pre‐announcement period. Last, the decline in information asymmetry around earnings announcements is closely associated with a lower participation rate in the pre‐announcement period and more active trading of retail investors after earnings releases.     

Capital structure around the world: The roles of firm- and country-specific determinants

We analyze the importance of firm-specific and country-specific factors in the leverage choice of firms from 42 countries around the world. Our analysis yields two new results. First, we find that firm-specific determinants of leverage differ across countries, while prior studies implicitly assume equal impact of these determinants. Second, although we concur with the conventional direct impact of country-specific factors on the capital structure of firms, we show that there is an indirect impact because country-specific factors also influence the roles of firm-specific determinants of leverage.     

Competitive and Information Effects of Cross-Border Stock Listings

We examine the effect of 269 cross‐border listings on rivals in the listing and domestic markets and find that U.S. rivals experience significant gains whereas domestic rivals do not. Both competitive and information effects are important in explaining the reaction of U.S. rivals. Regarding the competitive effects, the reaction of rivals is less favorable when listings originate in developed countries and more favorable when listing firms do not have prior operating presence in the United States. Regarding the information effects, the reaction is less favorable when listings are combined with equity offerings and more favorable when the listing is the first to occur within an industry.     

Finite sample multivariate structural change tests with application to energy demand models

This paper considers finite sample motivated structural change tests in the multivariate linear regression model with application to energy demand models, in which case commonly used structural change tests remain asymptotic. As in Dufour and Kiviet [1996. Exact tests for structural change in first-order dynamic models. Journal of Econometrics 70, 39–68], we account for intervening nuisance parameters through a two-stage maximized Monte Carlo test procedure. Our contributions can be classified into five categories: (i) we extend tests for which a finite-sample theory has been supplied for Gaussian distributions to the non-Gaussian context; (ii) we show that Bai et al. [1998. Testing and dating common breaks in multi-variate time series. The Review of Economic Studies 65 (3), 395–432] test severely over-rejects and propose exact variants of this test; (iii) we consider predictive break test approaches which generalize tests in Dufour [1980. Dummy variables and predictive tests for structural change. Economics Letters 6, 241–247] and Dufour and Kiviet [1996. Exact tests for structural change in first-order dynamic models. Journal of Econometrics 70, 39–68]; (iv) we propose exact (non-Bonferonni based) extensions of the multivariate outliers test from Wilks [1963. Multivariate statistical outliers. Sankhya Series A 25, 407–426] to models with covariates; (v) we apply these tests to the energy demand system analyzed by Arsenault et al. [1995. A total energy demand model of Québec: forecasting properties. Energy Economics 17 (2), 163–171]. For two out of the six industrial sectors analyzed over the 1962–2000 period, break and further goodness-of-fit and diagnostic tests allow to identify (and correct) specification problems arising from historical regulatory changes or (possibly random) industry-specific effects. The procedures we propose have potential useful applications in statistics, econometrics and finance (e.g. event studies).