从国际收支平衡表看我国产业结构存在的问题

一国国际收支结构特征本质上反映了其经济结构的特征,国际收支平衡表反映了一国对外负债、出口及进口产业的状况及变动。我国近几年的国际收支平衡表分析了当前产业结构存在的问题,所以,解决国际收支不平衡需要依赖产业结构的调整和市场关系的理顺,单纯依靠汇率升值是调整不过来的。     

注水泵机组磨损可靠性分析与评定

通过对注水泵机组磨损数据的统计处理,可得到寿命统计分布规律,并把握其可靠性数字特征,从而确定其可靠性指标;通过对不同机组磨损数据子样总体方差的显著性检验,可推断其总体寿命的稳定程度,并通过其子样总体均值的差异性检验,判断相互间磨损差异;通过对各台机组的趋势检验,得到各台机组的磨损趋势变化。这些对油田现场把握机组运行状况、合理安排检修,指导维修以及施工的经济性核算等环节有科学指导作用。     

Balance‐of‐payments‐constrained cyclical growth with distributive class conflicts and productivity dynamics

This study builds a dynamic balance‐of‐payments‐constrained model that incorporates the endogenous determination of the economic growth rate, conflictive wage/price distribution and employment rate. The wages, commodity prices and employment rate are determined by the profit squeeze effect and labour‐saving technical change. The relative strength of these two effects generates different outcomes for the transitional dynamics and comparative statics analysis. Particularly, the model shows stability, instability and cyclical nature, the latter of which concurs with the evidence reported by previous empirical studies.     

Volatility forecasts,proxies and loss functions

The main problem in volatility forecasting is that the variable of interest is unobservable, which complicates not only the construction of forecasts but also their comparison. This article challenges the common practice of using only proxy-robust loss functions, which have the nice property that they lead to the same ranking of forecasts regardless whether the unobservable true volatility is used or some unbiased proxy. It is shown that two proxy-robust loss functions need not necessarily produce similar rankings but may even produce completely contradictory rankings. Two likelihood-based loss functions are proposed instead, which are not exactly proxy-robust but are still robust in the classical sense. The first is based on a t-distribution and is meant for daily data. The second is based on an F-distribution and is meant for high-frequency data. In the latter case, the squared error loss function may also be used when a logarithmic transformation is applied to the realized variances in order to achieve approximate normality. An alternative transformation is proposed which allows the adaptation to the degree of non-normality. The forecasting procedures that are compared by the different loss functions include GARCH, HAR, HARQ, and MIDAS models as well as nonparametric techniques. Finally, the economic relevance of choosing the right forecast is illustrated with the problem of establishing the intertemporal risk–return tradeoff. All theoretical arguments are backed up with empirical evidence obtained from daily data as well as from high-frequency data.     

Bad volatility is not always bad: evidence from the commodity markets

ABSTRACT

Using exchange-traded fund (ETF) options data, we examine the predictive power of variance risk premium on returns of four commodities: crude oil, natural gas, gold and silver. We also analyze the predictive power of upside and downside variance risk premiums using a decomposition model conditional on the direction of the underlying market movement. We find that both the undecomposed and decomposed variance risk premiums are able to predict commodity prices. The decomposed variance risk premiums, however, outperform the undecomposed premium. The importance of upside and downside variance risk premiums differs across markets, related to hedging demand. In energy markets, both upside and downside premiums have strong predictive power, while in precious metal markets, only the upside premium is predictive.     

锚、网、带、索、喷联合支护

爆破后必须及时出碴，打锚杆眼、挂网、钢带、安装锚杆、喷碹一气呵成，尽量减少炮后岩体在无支护状态下的裸露时间（不超过2h），将喷碹由原来的原班一次改为每循环一次。新生煤矿在松软岩层中大力推广锚、网、带、锚索、喷联合支护技术，提高松软岩巷的掘进速度，尤其是在一采区水仓和水泵房以及紧急避难硐室掘进中取得了较好的效果。     

我国产业集群兴起与发展的理论研究——基于制度变迁、社会资本的分析

本文以我国由计划经济向市场经济的制度变迁过程为背景,分析了两种社会资本,即塑造型社会资本和沿袭型社会资本的动态变化对我国产业集群的兴起和发展所具有的双面效应:整合与激励的正面作用和阻碍与限制的负面效应,并提出了基于产业集群的社会资本重构。     

Volatility as an Asset Class: European Evidence

Abstract

Volatility movements are known to be negatively correlated with stock index returns. Hence, investing in volatility appears to be attractive for investors seeking risk diversification. The most common instruments for investing in pure volatility are variance swaps, which now enjoy an active over-the-counter (OTC) market. This paper investigates the risk-return tradeoff of variance swaps on the Deutscher Aktienindex and Euro STOXX 50 index over the time period from 1995 to 2004. We synthetically derive variance swap rates from the smile in option prices. Using quotes from two large investment banks over two months, we validate that the synthetic values are close to OTC market prices. We find that variance swap returns exhibit an option-like profile compared to returns of the underlying index. Given this pattern, it is crucial to account for the non-normality of returns in measuring the performance of variance swap investments. As in the US, the average returns of selling variance swaps are found to be strongly positive and too large to be compatible with standard equilibrium models. The magnitude of the estimated risk premium is related to variance uncertainty and past index returns. This indicates that the variance swap rate does not seem to incorporate all past information relevant for forecasting future realized variance.     

浅谈交流电梯平衡系数的检验案例

本文主要通过我们的一次对新办公大楼的新安装电梯进行监督检验的案例,对我国电梯的平衡系数进行了详细的探讨和研究,供同行参考。     

中部欠发达地区旅游用地规划研究——以湖北荆门市为例

在总结了中部地区旅游用地特点的基础上,重点从理论上分析了旅游用地规划中的旅游用地供需平衡这一关键问题,文章结合荆门市的实际情况,对荆门市的旅游用地展开研究;为确保规划的长期、有效和可持续发展;指出规划实施的保障措施和需注意的问题。