Labor productivity forecasts based on a Beveridge–Nelson filter: Is there statistical evidence for a slowdown?

In this paper, I assess the evidence for a structural break in labor productivity growth in the years before the Great Recession with the use of out-of-sample forecasting exercises for the years 2010 to 2019 and the recently developed Beveridge–Nelson filter. Models based on a Beveridge–Nelson filter with no structural breaks outperform those allowing for a structural break, and there is statistically significant evidence that they outperform the random walk, though all models were too optimistic about labor productivity growth. Recently developed statistical tests do point to the presence of a structural break before the Great Recession, but uncertainty about the data-generating process for labor productivity growth or the timing and magnitude of the break may be too great to be helpful in forecast preparation.     

Demystifying residents' walking behaviors: Active transport in South East Queensland,Australia

This study investigates the correlates of a resident's walking behaviors and aims to shed light on mechanisms through which walking may be encouraged. The results of this investigation paint a complex and nuanced picture of the residents’ walking behaviors in South East Queensland, Australia. The results suggest that sociodemographic characteristics separately may contribute greatly to whether or not one engages in walking behaviors. Further, cumulatively these differences might be greater for some groups of residents compared to others. One of the most prominent findings of the study is that the purpose, the characteristics of the origin, and the characteristics of the destination of a trip tended to be similar in the heterogeneity they exhibit over the distribution of time spent walking. For example, pick something up, undertake work, or engage in personal business, move to or from a workplace, shop, or social place are activities that tend to be associated with walking as a main mode of transport and a higher number of walking episodes. However, these trips tended to be short.     

EMI滤波器的设计

文章从建立EMI滤波器的共模、差模噪声源等效电路及电路模型入手,进而探讨了EMI滤波器的设计方法及其在实际应用的结构和结构参数的选择问题。     

Does subsidised temporary employment get the unemployed back to work? Aneconometric analysis of two different schemes

Subsidised employment is an important tool of active labour market policies to improve the reemployment chances of the unemployed. Using unusually informative individual data from administrative records, we investigate the effects of two different schemes of subsidised temporary employment implemented in Switzerland: non-profit employment programmes (EP) and a subsidy for temporary jobs (TEMP) in private and public firms. Econometric matching methods show that TEMP is more successful than EP in getting the unemployed back to work. Compared to not participating in any programme, EP and TEMP are ineffective for unemployed who find jobs easily anyway or have a short unemployment spell. For potential and actual long-term unemployed, both programmes may have positive effects, but the effect of TEMP is larger.     

消除工频干扰的自适应滤波器

工频干扰是仪器仪表信号中的重要干扰因素，要消除它，人们通常采用滤波方法，而采用自适应滤波的方法，可以取得较好的效果。     

Estimation methods for stochastic volatility models: a survey

Abstract.  Although stochastic volatility (SV) models have an intuitive appeal, their empirical application has been limited mainly due to difficulties involved in their estimation. The main problem is that the likelihood function is hard to evaluate. However, recently, several new estimation methods have been introduced and the literature on SV models has grown substantially. In this article, we review this literature. We describe the main estimators of the parameters and the underlying volatilities focusing on their advantages and limitations both from the theoretical and empirical point of view. We complete the survey with an application of the most important procedures to the S&P 500 stock price index.     

Explicit filters and supply chain design

Due to the complexity of present day supply chains it is important to select the simplest supply chain scheduling decision support system (DSS) which will determine and place orders satisfactorily. We propose to use a generic design framework, termed the explicit filter methodology, to achieve this objective. In doing so we compare the explicit filter approach to the implicit filter approach utilised in previous OR research the latter focusing on minimising a cost function. Although the eventual results may well be similar with both approaches it is much clearer to the designer, both why and how, an ordering system will reduce the Bullwhip effect via the explicit filter approach. The “explicit filter” approach produces a range of DSS designs corresponding to best practice. These may be “mixed and matched” to generate a number of competitive delivery pipelines to suit the specific business scenario.     

Testing the significance and the non-linearity of the Phillips trade-off in the Euro Area

This paper tests the significance and the non-linearity of the Phillips trade-off in the aggregate Euro Area, in an unobserved components model of stochastic NAIRU and trend output featuring the Phillips equation and the Okun law as main identifying equations, with quarterly data for 1970:I-2002:III. The Phillips curve turns out to be linear and its trade-off statistically significant, while non-linearity shows up in the Okun relation. The results prove to be robust to alternative lag length structures of the model, and to alternative non-linear functional forms. The trend-cycle decompositions estimated with the model capture the main features of the Euro Area’s recent macroeconomic record.First version received: 1 September 2003 / Final version received: June 2004CEMPRE - Centro de Estudos Macroeconómicos e Previsão - is supported by the Fundação para a Ciência e a Tecnologia, Portugal, through the Programa Operacional Ciência, Tecnologia e Inovação (POCTI) of the Quadro Comunitário de Apoio III, which is financed by FEDER and Portuguese funds.We thank comments on earlier versions by Fabio Canova, Miguel St Aubyn, Alvaro Almeida, Pete Richardson, Kevin Ross, and two anonymous referees. We acknowledge James D. Hamilton’s help with the confidence bands. The usual disclaimer applies.     

Forecasting UK house prices: A time varying coefficient approach

Previous studies of UK house prices, developed from the demand and supply ofhousing or from the asset market approach have been poor in terms of robustness and ex-post forecasting ability. The UK housing market has suffered a number of structural changes, particularly since the early 1980s with substantial house price increases, financial market deregulation and the removal of mortgage market constraints through competition. Consequently, models which assume that the underlying data-generating process is stable and apply constant parameter techniques tend to suffer in terms of parameter instability. This article uses the Time Varying Coefficient (TVC) methodology where the underlying data-generating process in the UK housing market is treated as unstable. The estimation results of the TVC regression of UK house prices is compared with those obtained from three alternative constant parameter regressions. Comparisons of forecasting performance suggest the TVC regression out-performs forecasts from an Error Correction Mechanism (ECM), Vector Autoregressive (VAR) and an Autoregressive Time Series regression.     

曝气生物滤池及其填料作用机理

介绍了曝气生物滤池及其填料的应用情况和研究进展,对曝气生物滤池反应动力学以及其填料作用机理等方面的研究进展进行了研究,概述了影响曝气生物滤池运行的主要因素,同时提出了今后曝气生物滤池的发展方向。