Farms’ technical inefficiencies in the presence of government programs*

We focus on determining the impacts of government programs on farms’ technical inefficiency levels. We use Kumbhakar's stochastic frontier model that accounts for both production risks and risk preferences. Our theoretical framework shows that decoupled government transfers are likely to increase (decrease) DARA (IARA) farmers’ production inefficiencies if variable inputs are risk decreasing. However, the impacts of decoupled payments cannot be anticipated if variable inputs are risk increasing. We use farm‐level data collected in Kansas to illustrate the model.     

Investment planning under uncertainty and flexibility: the case of a purchasable sales contract*

Investment decisions are not only characterised by irreversibility and uncertainty but also by flexibility with regard to the timing of the investment. This paper describes how stochastic simulation can be successfully integrated into a backward recursive programming approach in the context of flexible investment planning. We apply this hybrid approach to a marketing question from primary production which can be viewed as an investment problem: should grain farmers purchase sales contracts which guarantee fixed product prices over the next 10 years? The model results support the conclusion from dynamic investment theory that it is essential to take simultaneously account of uncertainty and flexibility.     

互联网企业价值评估模型比较研究

基于互联网企业轻资产、高估值、迭代快以及风险大等特点,比较传统价值评估模型与Schwar-tz-Moon等实物期权价值评估模型,分别运用于评估案例企业泛微网络价值.结果发现,相较于传统现金流贴现模型,实物期权价值评估模型评估结果更接近于公司实际价值.三种实物期权模型敏感性分析表明:Schwartz-Moon模型评估误差最小,且模型稳健性最强,适用于不确定性高的互联网企业估值.     

Spillovers in Exchange Rates and the Effects of Global Shocks on Emerging Market Currencies

This paper provides an investigation into the spillover effects of exchange rate returns and volatility for developed and emerging market currencies, using data from 1997 to 2011. The results suggest that spillovers in exchange rate returns have increased steadily over time, in moderate reaction to economic events. In contrast, spillovers in total observed volatility (measured by squared returns) react more strongly to economic events, and this transmission has remained at a relatively high level since the global financial crisis. Furthermore, over the course of time, global shocks would appear to account for a larger proportion of aggregate exchange rate volatility (and the relative importance of domestic shocks has declined). The paper also considers whether the increase in volatility spillover is due to sudden shocks, or whether it is due to changes in the stochastic trend of the underlying volatility process. The results suggests that in most cases, this increase is due to sudden shocks, however, in certain instances country‐specific events may perpetuate changes to the trend of the underlying volatility spillover.     

金融冲击、货币政策与宏观审慎政策—基于动态随机一般均衡模型的分析

通过建立包含房地产市场金融冲击的NK-DSGE模型,考察了我国货币政策与宏观审慎政策的效果。通过比较不同政策机制下金融冲击的脉冲响应函数可以发现,宏观审慎政策的引入缓和了金融冲击的效应,并且可以同时实现稳定物价和稳定金融系统的目的。社会福利分析的结果表明：(1)金融冲击下,仅对产出缺口和通胀做出反应的政策具有最低的社会福利水平;(2)如果货币政策考虑信贷市场,并同时使用反周期性宏观审慎政策,那么社会福利将得到明显的提高。这意味着金融冲击下,政府应该积极行使对信贷市场做出反应的货币政策以及反周期性宏观审慎政策相结合的政策机制。当前,在房地产市场整体不景气的背景下,我国政府积极利用金融冲击对房地产市场进行调控。因此,采用对信贷市场做出反应的货币政策以及反周期性宏观审慎政策将具有相对较好的政策效果。     

县(市)级土地利用总体规划中耕地需求量预测方法及其应用

科学准确地预测耕地需求量,是制定县(市)级土地利用总体规划的基础.文章根据中国南方某县1996-2005年来的耕地变更调查统计数据,分别采用趋势分析法、回归分析法、指数平滑法、GM(1,1)模型法和灰色-马尔柯夫链模型的方法,对该地区耕地总量进行了模拟和预测.不同方法的预测结果表明,基于灰色-马尔柯夫链方法的预测结果更加准确可靠,更有利于土地管理决策者的经济决策行为.在当前耕地利用方式的背景下,灰色-马尔柯夫链模型可以作为县(市)级土地利用总体规划中耕地需求量预测方法的一种好选择.     

大型沉管管节浮运航道适航特性建模分析

为确保沉管隧道在航道中长期浮运作业的安全性与可靠性,依托深中通道工程备选预制厂方案,建立珠江口局部区域二维水流数学模型,在实测水文资料验证的基础上,通过模型计算揭示了浮运航道的水动力变化特征,开展航道范围内横流、纵流的变化特点分析.分析结果表明:工程实施后,龙穴港池水域的潮流流速普遍较弱,南沙四期港池水域流速变化较小,...     

Can negative interest rates really affect option pricing? Empirical evidence from an explicitly solvable stochastic volatility model

The profound financial crisis generated by the collapse of Lehman Brothers and the European sovereign debt crisis in 2011 have caused negative values of government bond yields both in the USA and in the EURO area. This paper investigates whether the use of models which allow for negative interest rates can improve option pricing and implied volatility forecasting. This is done with special attention to foreign exchange and index options. To this end, we carried out an empirical analysis on the prices of call and put options on the US S&P 500 index and Eurodollar futures using a generalization of the Heston model in the stochastic interest rate framework. Specifically, the dynamics of the option’s underlying asset is described by two factors: a stochastic variance and a stochastic interest rate. The volatility is not allowed to be negative, but the interest rate is. Explicit formulas for the transition probability density function and moments are derived. These formulas are used to estimate the model parameters efficiently. Three empirical analyses are illustrated. The first two show that the use of models which allow for negative interest rates can efficiently reproduce implied volatility and forecast option prices (i.e. S&P index and foreign exchange options). The last studies how the US three-month government bond yield affects the US S&P 500 index.     

Short-time at-the-money skew and rough fractional volatility

The Black–Scholes implied volatility skew at the money of SPX options is known to obey a power law with respect to the time to maturity. We construct a model of the underlying asset price process which is dynamically consistent to the power law. The volatility process of the model is driven by a fractional Brownian motion with Hurst parameter less than half. The fractional Brownian motion is correlated with a Brownian motion which drives the asset price process. We derive an asymptotic expansion of the implied volatility as the time to maturity tends to zero. For this purpose, we introduce a new approach to validate such an expansion, which enables us to treat more general models than in the literature. The local-stochastic volatility model is treated as well under an essentially minimal regularity condition in order to show such a standard model cannot be dynamically consistent to the power law.     

Momentum in the Chinese Stock Market: Evidence from Stochastic Oscillator Indicators

ABSTRACT

We explore whether investors earn profits through the use of stochastic oscillator indicators (SOI) for trading stocks. The results reveal that investors might use momentum strategies when trading constituent stocks of SSE 50 as the overbought trading signals emitted by SOI. We infer that the results might be caused by herding behaviors of Chinese investors since overoptimistic moods are likely to exist as evidenced by the 80 percent trading volume traded by individual investors in the Chinese stock market.