Testing for unit roots in time series models with non-stationary volatility

Many of the key macro-economic and financial variables in developed economies are characterized by permanent volatility shifts. It is known that conventional unit root tests are potentially unreliable in the presence of such behaviour, depending on a particular function (the variance profile) of the underlying volatility process. Somewhat surprisingly then, very little work has been undertaken to develop unit root tests which are robust to the presence of permanent volatility shifts. In this paper we fill this gap in the literature by proposing tests which are valid in the presence of a quite general class of permanent variance changes which includes single and multiple (abrupt and smooth-transition) volatility change processes as special cases. Our solution uses numerical methods to simulate the asymptotic null distribution of the statistics based on a consistent estimate of the variance profile which we also develop. The practitioner is not required to specify a parametric model for volatility. An empirical illustration using producer price inflation series from the Stock–Watson database is reported.     

自由现金流量、股权结构与我国上市公司过度投资问题研究

按照自由现金流量假说,当公司存在大量自由现金流量时,管理人员的机会主义行为容易引发过 度投资.本文以2005-2007年上市公司数据考察我国企业是否存在过度投资以及股权结构能否抑制过度投资.分析表明我国企业普遍存在过度投资行为,国有企业相比非国有企业过度投资更严重,现金流与投资行为显著正相关,第一大股东持股比例与股权集中度在某种程度上能够制约过度投资,但是举债在我国并不能对过度投资发挥有效的抑制作用.     

海峡两岸证券业经营效率比较研究:基于Metafrontier方法

本文将Metafrontier思想与BCC-DEA模型相结合,综合应用Metafrontier DEA方法、Malmquist全要素生产率指数和Tobit模型,客观地评价具有不同生产技术的两岸证券商的经营效率。结果表明:台湾证券商发展水平趋同,大陆证券商良莠不齐,但竞争力逐渐提升;台湾证券商技术水平落后于大陆;大陆全要素生产率逐渐改善,台湾逐渐衰退;资产总额、负债比、地区生产总值是影响技术效率的关键因素,负债比、经济自由度、地区生产总值是影响技术落差的关键因素;金融危机对两岸证券业冲击显著。     

An effective hybrid variance reduction method for pricing the Asian options and its variants

In this paper, we propose a variance reduction method that combines importance sampling and control variates to price European Arithmetic Asian options and its variants (i.e., Asian options plus knock-in or knock-out options) under the Black-Scholes model. The numerical results show that the proposed methods are especially efficient under the following scenarios: in the money, low volatility, more sampling dates, and higher barrier thresholds.     

我国工业化过程与电力消费弹性系数演变过程的相关性

本文首先论述了电力消耗与经济发展过程的一般规律、电力消费弹性系数的演变规律和我国电力消费弹性系数的演变过程,然后分析了我国工业化过程与电力消费弹性系数演变过程的相关性,最后概括了主要结论并且提出了两个需要思考的问题。研究发现,由于我国正处于重工业化时期,电力消费弹性系数明显地大于1,而且第二产业耗费电力能源的比例持续上升。     

Theoretical analysis and model design of search for ecological conservation redlines based on the sensitivity assessment of ecosystem services

Most small-scale social economies are characterised by their deficiency, lack, and/or difficulty in matching natural data. Against this backdrop, this paper builds a relatively uniform theoretical framework and designs a more economical and objective method for demarcating ecological conservation redlines (ECR) based on sensitivity assessment of ecosystem services. The results show that the sensitivity assessment model designed in this study can identify sensitive zones effectively, and that the ECR in Hubei Province are well within the sensitive zones so identified. The delimited areas based on the sensitive assessment of ecosystem services have great similarities (95%) with the actual ECR areas in Hubei Province. The most ecologically important functional zones (EIFZ) can also be identified using the regional ecological sensitivity coefficient. When the threshold of EIFZ is set higher, the probability that it falls within the ecologically sensitive areas is greater and the ECR delimited by the method proposed in this study will be more reliable. Theoretically, the delimitation of ECR can be inserted at any evaluation level with a grid resolution higher than that of the land use data, which can be used as a supplement to the ECR delimitation method in ecology or geography.     

Panel LM unit root tests with level and trend shifts

This paper considers a Lagrange multiplier (LM) based panel unit root test that allows for heterogeneous structural breaks in both the intercepts and slopes of a series. We note that many popular time series variables are likely to exhibit changing means and/or trends over time. Given that the usual tests will depend on the nuisance parameters indicating the locations of the trend breaks, we adopt a transformation procedure that makes our new panel unit root tests invariant to the nuisance parameters. To illustrate the importance of the power gain provided by our test, we examine the convergence hypothesis using relative ratios of per capita health care expenditures in 20 OECD countries. Our results provide evidence that the convergence hypothesis is supported.     

Capital account flows,consumption ratios and the middle‐income trap

The existing literature suggests that it is important to understand the factors that may slow the transition of an economy from middle to high income. Many factors have been suggested as promoting or retarding economic growth, but little attention has been paid to the roles of the capital account and consumption ratio. Using panel regressions involving 48 countries over the 1950–2013 period as well as employing extreme bounds analysis, we find that foreign investment outflows are associated with a mature economy and that there is an optimal consumption ratio that must be surpassed to break out of middle‐income status. These findings are robust to an extreme bounds analysis incorporating a wide range of variables potentially related to growth performance.     

Asymmetry,Complementarities, and State Dependence in Federal Reserve Forecasts

Forecasts are a central component of policymaking; the Federal Reserve's forecasts are published in a document called the Greenbook. Previous studies of the Greenbook's inflation forecasts have found them to be rationalizable but asymmetric if considering particular subperiods, for example, before and after the Volcker appointment. In these papers, forecasts are analyzed in isolation, assuming policymakers value them independently. We analyze the Greenbook forecasts in a framework in which the forecast errors for different variables are allowed to interact. We find that allowing the losses to interact makes the unemployment forecasts virtually symmetric, the output forecasts symmetric prior to the Volcker appointment, and the inflation forecasts symmetric after the onset of the Great Moderation.     

Quantitative easing and the loan to collateral value ratio

We study optimal monetary policy in a New Keynesian model at the zero bound interest rate where households use cash alongside house equity borrowing to conduct transactions. The amount of borrowing is limited by a collateral constraint. When either the loan to value ratio declines or house prices fall, we observe a decrease in the money multiplier. We argue that the central bank should respond to the fall in the money multiplier and therefore to the reduction in house prices or the loan to collateral value ratio. We also find that optimal monetary policy generates a large and persistent fall in the money multiplier in response to the drop in the loan to collateral value ratio.