Factors Influencing Organic and Fair Trade Coffee Growers Level of Engagement with Cooperatives: The Case of Coffee Farmers in Mexico

We study the factors influencing the percentage of organic and fair trade certified coffee sold through a cooperative by growers of five cooperatives in Mexico. The percentage of coffee sold through the cooperative was used as a proxy of growers’ engagement with a cooperative. Using factor analysis and a fractional probit regression, we evaluated the proposition that the level of engagement can be explained by transaction cost economics, social norms and connections, and farmer and farm business characteristics. We found that farm size, uncertainty regarding cooperative time of payment to the members and cooperative commitment on price to be paid negatively influence the level of engagement. In contrast, asset specificity, relational commitment, and price have a positive impact on engagement. Our results may help cooperatives and policy makers to build strategies aiming to increase this level of engagement. This is relevant because lower grower engagement has been found to be positively correlated with weak performing cooperatives.     

寡头博弈模型中的时间记忆性质与预期对模型稳定性的影响

公平竞争是市场经济的灵魂,是发挥市场力量的关键.研究寡头垄断企业的竞争行为和竞争环境对中国强化反垄断,构建更加安全公平、有效竞争的经济市场意义重大.梳理寡头垄断企业中的价格竞争和产量竞争中的模型稳定性研究情况,通过模型的边界均衡点和局部均衡点来分析模型的稳定性,对寡头博弈模型中时间的记忆性与预期对模型稳定性的影响进行分析.     

Mozambique Metical Exchange Rate Dynamics: Evidence of Fractional Co‐Integration in the USA and South African Rates

This paper studies the exchange rate dynamics of the Mozambique metical with respect to the US dollar and the South African rand. However, instead of using standard I(0)/I(1) techniques, we use long memory and fractionally integrated and co‐integrated models. Our results indicate that the two exchange rates are highly persistent, with orders of integration equal to or above 1. They also seem to be co‐integrated, with an order of integration close to albeit above 0 but with an AR coefficient very close to 1. Thus, although the two series seem to be fractionally co‐integrated, shocks in the long‐run relationship between the two variables are persistent and take a long time to disappear.     

碳债券的估值及敏感性分析

论文以2014年5月13日中广核电附加碳收益中期票据的成功发行为背景,在假设核证碳减排量(CER)服从几何分形过程的情况下,结合分形过程的蒙特卡洛模拟,研究了中期碳债券的设计和估值问题,并分析了不同的期权条款设计带来的风险差异。研究认为相对较复杂的强路径依赖型亚式浮息碳债券,在碳现货价格波动性较大的情况下,简单的欧式浮息碳债券是更好的设计选择。     

Volatility of volatility is (also) rough

Using high-frequency data for major volatility indexes, we compute the volatility of volatility and show that its logarithm follows a fractional Brownian motion with Hurst parameter smaller than 1/2 thereby extending to the volatility asset class the recent findings obtained for the equity index markets. The results confirm that the volatility of volatility is a rough process and it possesses the long memory property. We also show that the correlation between the volatility and the volatility of volatility is positive, consistent with observations in the volatility option market. Lastly, a robustness check using volatility futures confirms the findings.     

The characteristic function of rough Heston models

It has been recently shown that rough volatility models, where the volatility is driven by a fractional Brownian motion with small Hurst parameter, provide very relevant dynamics in order to reproduce the behavior of both historical and implied volatilities. However, due to the non‐Markovian nature of the fractional Brownian motion, they raise new issues when it comes to derivatives pricing. Using an original link between nearly unstable Hawkes processes and fractional volatility models, we compute the characteristic function of the log‐price in rough Heston models. In the classical Heston model, the characteristic function is expressed in terms of the solution of a Riccati equation. Here, we show that rough Heston models exhibit quite a similar structure, the Riccati equation being replaced by a fractional Riccati equation.     

Fractional integration and cointegration in merger and acquisitions in the US petroleum industry

This article employs methodologies based on fractional integration and cointegration to analyse the time-series properties of merger and acquisitions (M&A) activity and crude oil prices in the US from 1980 to 2012. Our results indicate that an increase in the crude oil price produces a significant increase in the M&A data between 2 and 3 months after the initial shock.     

ECONOMIC RECESSIONS,BANKING REFORM AND THE FUTURE OF CAPITALISM1

In the 2010 London School of Economics and Political Science Hayek Memorial Lecture, the author argues that flaws in the design of the monetary and financial system were responsible for the global financial crisis and the subsequent recession. The crash reflected the unsustainable nature of the bubble induced by artificial credit expansion created by fractional‐reserve banking under the direction of central banks. Such boom–bust cycles will continue until radical reforms are implemented, including a 100% reserve requirement for demand deposits.     

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.     

Measuring persistence in Croatian tourism: evidence from the Adriatic region

This study examines the degree of persistence in foreign tourist arrivals and overnight stays for seven Croatian coastal counties over the period January 1998 to December 2013 using fractional integration techniques. Our findings reveal that the respective regional tourism indicators exhibit seasonal unit roots which require seasonal first differences to render the respective time series stationary. With respect to the long-run evolution of the respective time series, both the parametric and semi-parametric fractional integration approaches show the degree of persistence is greater than zero, but significantly less than one for the majority of the coastal counties. Impulse response analysis reveals indeed shocks to the deseasonalized time series, either foreign tourist arrivals or foreign tourist overnight stays, appear short-lived with the exception of Istria and Primorje-Gorski kotar counties. Policy implications of the results are also discussed.