Spurious relationships in high-dimensional systems with strong or mild persistence

This paper is concerned with the interactions of persistence and dimensionality in the context of the eigenvalue estimation problem of large covariance matrices arising in cointegration and principal component analysis. Following a review of the early and more recent developments in this area, we investigate the behaviour of these eigenvalues in a vector autoregression setting that blends pure unit root, local to unit root and mildly integrated components. Our results highlight the seriousness of spurious relationships that may arise in such big data environments even when the degree of persistence of the variables involved is mild and affects only a small proportion of a large data matrix, with important implications for forecasts based on principal component regressions and related methods. We argue that, prior to principal component analysis, first-differencing may be suitable even in stationary or nearly stationary environments.     

Hedge fund return,volatility asymmetry,and systemic effects: A higher-moment factor-EGARCH model

We investigate whether: (i) co-skewness and co-kurtosis are significant factors in modeling hedge fund (HF) returns, (ii) HF return volatility displays clusters, asymmetry and shock persistence, (iii) volatility clusters of HF styles drive volatility clusters of one another, major asset classes, and major banking organizations, (iv) HF return and volatility patterns changed after the financial crises of 1998 and 2007–2009. A higher-moment EGARCH model and monthly data over January 1993–April 2014 period on 13 HF styles are employed. Out-of-sample forecasts are generated over the period of May 2014–April 2016. Results show: (i) most of the co-skewness and co-kurtosis coefficients are statistically significant, strongly supporting the higher-moment return generating models; (ii) there is strong evidence in favor of EGARCH specification, volatility clustering, asymmetry, and shock persistence; (iii) there were distinct effects on the returns and volatilities of HFs during the 1998 Russian bond crisis, Long-Term Capital Management crisis, and the 2007–2009 financial crisis; and (iv) shocks to volatility clusters of a HF style do spillover to other HF styles, major banking firms, and key asset classes. Our findings have major implications for regulators, investors, HF managers and hedging strategists.     

On the robustness of persistence in mutual fund performance

This paper analyzes persistence in US equity mutual fund performance over the period 1990–2015. We apply commonly used measures of persistence, which we test using a set of simulated passive funds. In the first stage we apply contingency tables and transition matrices in accordance with previous literature. Results show how these methodologies are biased towards finding evidence of persistence too easily. In the second stage, we take a recursive portfolio approach, which assesses the performance of investing by following recommendations based on past performance. Results show the importance of both estimating persistence by distinguishing among fund style groups, and considering the cross-sectional significance of recursive portfolios. In general, our results support evidence of persistence in mutual fund performance, especially for the case of the best mutual funds. However, this evidence does not hold for the most recent subperiod, 2008–2015. Empirical evidence of persistence is conditioned by the sample period, a result that could explain the inconclusive results found in the literature.     

现金流组成要素对企业盈利能力的预测作用——基于核心与非核心现金流

本文选取757家沪深A股上市公司2006-2009年的数据作为研究样本,考察了在企业的现金流组成要素中,不同要素对于企业盈利现状的解释能力和对盈利前景的预测能力有何差异,以及不同要素的盈余持续性有何差异。研究发现:(1)拆分后的现金流比现金流总额对盈余和股票报酬具有更强的解释和预测能力。(2)核心现金流对盈余和股票报酬率的解释和预测作用比非核心现金流的要强。(3)核心现金流的盈余持续性比非核心现金流的要强。本文的研究结果为今后盈利预测研究充分挖掘现金流组成要素的信息含量和预测价值提供了实证依据。     

中国大米市场回归均衡速度研究

本文利用持续性时间序列（Persistence profile）方法分粳米和籼米估计了大米市场受到冲击后向均衡收敛的速度，进而分析了中国大米市场的有效性，研究结果表明：对于粳米而言，主产地市场比主销地市场更有效；从总体上看，籼米市场比粳米市场更有效。为缩短市场受到冲击后回到均衡需要的时问，提高中国大米市场的有效性，粳米主销地要储备合理数量的粳米应对市场的突然冲击，要采取多种措施与主产区建立稳定的大米购销关系；国家要加强粮食市场信息化和交通运输建设，提高大米流通效率，加快市场调节速度。     

BN周期成分的符号与我国GDP的真实周期

本文从理论上证明了以下的定理：当度量序列持久性的方差比大于1时,BN周期成分的符号应予反号,否则,不予反号。为验证定理,我们设计Monter-Carlo仿真实验,其结果也证实了理论定理。本文的理论结论和仿真结果,第一次从持久性的角度解释了文献中的“周期之谜”。在此基础上,我们应用BN周期分解方法和本文的理论结果,分解我国GDP的BN周期。结果显示,由于我国GDP的方差比为1.97,所以周期成分的符号应反号,由此形成我国GDP的真实周期。样本期内（2000Q2-2011Q4）我国共经历了六轮周期,这六轮周期不仅与我国实际经济增长的波动基本一致,而且与我国所遭遇的主要冲击相吻合;我国经济增长的周期具有波动幅度较大、持续时间又存在明显差异的特征。基于这些特征,本文认为,减弱我国经济增长的周期性波动,应成为宏观调控的重要内容。     

Inflation persistence during periods of structural change: an assessment using Greek data

The paper estimates inflation persistence in Greece from 1975 to 2003, a period of high variation in inflation and changes in policy regimes. Two empirical methodologies, univariate autoregressive (AR) modelling and second-generation random coefficient (RC) modelling, are employed to estimate inflation persistence. The empirical results from all the procedures suggest that inflation persistence was high till 1996, while it started to decline after 1997, when inflationary expectations seem to have been stabilised, and thus, monetary policy was effective at reducing inflation. Empirical findings also detect a sluggish response of inflation to changes in monetary policy. This observed delay seems to have changed little over time.

CLIOMETRICS AND TIME SERIES ECONOMETRICS: SOME THEORY AND APPLICATIONS

Abstract The paper discusses a range of modern time series methods that have become popular in the past 20 years and considers their usefulness for cliometrics research both in theory and via a range of applications. Issues such as, spurious regression, unit roots, cointegration, persistence, causality, structural time series methods, including time varying parameter models, are introduced as are the estimation and testing implications that they involve. Applications include a discussion of the timing and potential causes of the British Industrial Revolution, income ‘convergence’ and the long‐run behaviour of English real wages 1264–1913. Finally some new and potentially useful developments are discussed including the mildly explosive processes; graphical modelling and long memory.     

The fallacy of “only the strong survive”: The effects of extrinsic motivation on the persistence decisions for under-performing firms

Under-performing firms persist even though existing theoretical perspectives indicate that they should be selected out of the market. Building upon threshold theory [Gimeno, J., Folta, T., Cooper, A., Woo, C., 1997. Survival of the fittest? Entrepreneurial human capital and the persistence of underperforming firms. Administrative Science Quarterly 42, 750–783.] and using Staw's [Staw, B.M., 1981. The escalation of commitment to a course of action. Academy of Management Review 6 (4), 577–587.] theoretical model of commitment to a course of action, we explore and test the factors that lead entrepreneurs to persist with under-performing firms. We found environmental munificence, personal investment, personal options, previous organizational success, and perceived collective efficacy impact the decision to persist with an under-performing firm. In addition, extrinsic motivation moderates those relationships. This research adds to the growing literature on highly persistent, under-performing firms and complements and extends threshold theory.     

Common persistence in conditional variance: A reconsideration

This paper demonstrates the flaws of co-persistence theory proposed by Bollerslev and Engle (1993) which cause the theory can hardly be applied. With the introduction of the half-life of decay coefficient as the measure of the persistence, and both the weak definition of persistence and co-persistence in variance, this study attempts to solve the problems by using exhaustive search algorithm for obtaining co-persistent vector. In addition, this method is illustrated to research the co-persistence of stock return volatility in 10 European countries.