Conditional risk measures in a bipartite market structure

In this paper, we study the effect of network structure between agents and objects on measures for systemic risk. We model the influence of sharing large exogeneous losses to the financial or (re)insurance market by a bipartite graph. Using Pareto-tailed losses and multivariate regular variation, we obtain asymptotic results for conditional risk measures based on the Value-at-Risk and the Conditional Tail Expectation. These results allow us to assess the influence of an individual institution on the systemic or market risk and vice versa through a collection of conditional risk measures. For large markets, Poisson approximations of the relevant constants are provided. Differences of the conditional risk measures for an underlying homogeneous and inhomogeneous random graph are illustrated by simulations.     

Dynamics of quote and deal prices in the foreign exchange market

We empirically investigate price fluctuations of yen-dollar exchange rate using the high-frequency data recorded in the electronic broking system for seven-year period. The distribution of quote price changes has symmetric fat-tails approximated by a power law; however, that of deal price is asymmetrical. The autocorrelation function and diffusion of price changes indicate that quote price exhibits anti-correlation feature in short time scale, whereas deal price is essentially uncorrelated. The bid-ask spread shows power-law distribution and long range temporal correlations similar to that observed in absoute price changes.      

3M公司汽车市场新产品扩散模型分析

基于BASS模型,对3M公司历年来汽车相关产品销售历史数据利用非线性最小二乘法拟合扩散系数和创新系数。通过对扩散系数和创新系数的分布特性的研究,发现3M公司不同类别新产品有各自类似的市场扩散特性。     

基于烟羽模型的交通影响范围模型的研究

从烟羽模型法应用于确定交通影响范围的建模过程分析入手，指出其存在的不足，修正了类比假设的不合理，通过合理假设，建立了一个能定量化、实用性较强的确定拟建项目交通影响范围的模型，并举以实例。     

Quadratic Hawkes processes for financial prices

We introduce and establish the main properties of QHawkes (‘Quadratic’ Hawkes) models. QHawkes models generalize the Hawkes price models introduced in Bacry and Muzy [Quant. Finance, 2014, 14(7), 1147–1166], by allowing feedback effects in the jump intensity that are linear and quadratic in past returns. Our model exhibits two main properties that we believe are crucial in the modelling and the understanding of the volatility process: first, the model is time-reversal asymmetric, similar to financial markets whose time evolution has a preferred direction. Second, it generates a multiplicative, fat-tailed volatility process, that we characterize in detail in the case of exponentially decaying kernels, and which is linked to Pearson diffusions in the continuous limit. Several other interesting properties of QHawkes processes are discussed, in particular the fact that they can generate long memory without necessarily being at the critical point. A non-parametric fit of the QHawkes model on NYSE stock data shows that the off-diagonal component of the quadratic kernel indeed has a structure that standard Hawkes models fail to reproduce. We provide numerical simulations of our calibrated QHawkes model which is indeed seen to reproduce, with only a small amount of quadratic non-linearity, the correct magnitude of fat-tails and time reversal asymmetry seen in empirical time series.     

Target volatility option pricing in the lognormal fractional SABR model

We examine in this article the pricing of target volatility options in the lognormal fractional SABR model. A decomposition formula of Itô's calculus yields an approximation formula for the price of a target volatility option in small time by the technique of freezing the coefficient. A decomposition formula in terms of Malliavin derivatives is also provided. Alternatively, we also derive closed form expressions for a small volatility of volatility expansion of the price of a target volatility option. Numerical experiments show the accuracy of the approximations over a reasonably wide range of parameters.     

Information diffusion and the predictability of New Zealand stock market returns

This paper examines the impact of international predictors from liquid markets on the predictability of excess returns in the New Zealand stock market using data from May 1992 to February 2011. We find that US stock market return and VIX contribute significantly to the out‐of‐sample forecasts at short horizons even after controlling for the effect of local predictors, while the contribution by Australian stock market return is not significant. We further demonstrate that the predictability of New Zealand stock market returns using US market predictors could be explained by the information diffusion between these two countries.     

区域经济创新扩散强度与效应研究——以京津冀和长三角地区为例

科技中心城市对周边腹地的技术创新扩散强度和效应对区域技术进步具有举足轻重的作用。运用基于VAR模型的脉冲响应函数测度北京与上海的扩散强度与效应之后,其结果表明：北京扩散的强度以及效应都较弱于上海。因此,北京应弱化政府在科技资源配置中的作用,努力培育企业作为创新主体,提高自身对京津冀区域内其他地区的扩散的强度。     

Detecting self-organisational change in economic processes exhibiting logistic growth

This paper offers an econometric methodology for the detection of self-organisational change (defined in terms of the presence of time irreversibility, structural change and fundamental uncertainty) in economic processes that follow logistic diffusion growth paths in historical time. The approach we adopted is built upon recent developments in `moving window' spectral methods which are applied to the scaled residuals generated by estimated logistic diffusion models. We illustrate the use of such methods by examining the case of a financial instrument, namely, the Australian Building Society Deposit, which experienced logistic growth in its market share until bank deregulation was enacted in the 1980s. We show that there is clear evidence that self-organisational change is present over the historical period considered.