Flexible estimation of price response functions using retail scanner data

Kalyanam and Shively [1998. Estimating irregular pricing effects: a stochastic spline regression approach. Journal of Marketing Research 35 (1), 16–29] and van Heerde et al. [2001. Semiparametric analysis to estimate the deal effect curve. Journal of Marketing Research 38 (2), 197–215] have demonstrated the usefulness of nonparametric regression to estimate pricing effects flexibly. The empirical results of these two studies, however, also revealed that nonparametric regression may suffer from too much flexibility leading to nonmonotonic shapes for price effects. In this paper, we show how the problem of nonmonotonicity can be dealt with without losing the power of flexible estimation techniques. We propose a semiparametric approach based on Bayesian P-splines with monotonicity constraints imposed on own- and cross-price effects. In an empirical application, we illustrate that flexible estimation of own- and cross-price effects can improve the predictive validity of a sales response model substantially, even when price response curves were constrained to show a monotonic shape, as suggested by economic theory. We also discuss the consequences from an unconstrained estimation of price effects.     

基于MBP算法和深度学习的人脸识别

为了解决在深度学习提取人脸图像特征时,易忽略其局部结构特征和缺乏对其旋转不变性学习的问题,提出了一种基于单演局部二值模式(MBP)与深度学习相结合的高效率人脸识别方法。首先,用多尺度单演滤波器对图像进行滤波,得到幅值和方向信息;其次,用LBP算法和象限比特的方法进行编码,分块计算组合其直方图特征;然后,将提取的单演特征作为深度信念网络(DBN)的输入,逐层训练优化网络参数,得到优异的网络模型;最后,将训练好的DBN网络在ORL人脸数据库上进行人脸识别实验,进行识别率计算,其识别率为98.75%。所提出的方法使用无监督的贪婪算法,隐藏层设定为2层,使用反向传播算法优化网络。相较于已知的人脸识别方法,MBP+DBN算法对光照、表情和部分遮挡变化具有较好的鲁棒性,在人脸识别中识别率较高,具有一定的优势,为图像特征提供了一种新的识别方法。     

A new multiscale decomposition ensemble approach for forecasting exchange rates

Due to the high complexity and strong nonlinearity nature of foreign exchange rates, how to forecast foreign exchange rate accurately is regarded as a challenging research topic. Therefore, developing highly accurate forecasting method is of great significance to investors and policy makers. A new multiscale decomposition ensemble approach to forecast foreign exchange rates is proposed in this paper. In the approach, the variational mode decomposition (VMD) method is utilized to divide foreign exchange rates into a finite number of subcomponents; the support vector neural network (SVNN) technique is used to model and forecast each subcomponent respectively; another SVNN technique is utilized to integrate the forecasting results of each subcomponent to generate the final forecast results. To verify the superiority of the proposed approach, four major exchange rates were chosen for model comparison and evaluation. The experimental results indicate that our proposed VMD-SVNN-SVNN multiscale decomposition ensemble approach outperforms some other benchmarks in terms of forecasting accuracy and statistical tests. This demonstrates that our proposed VMD-SVNN-SVNN multiscale decomposition ensemble approach is promising for forecasting foreign exchange rates.     

宗地规模、城市类型与土地出让溢价——基于70个大中城市住宅用地出让数据的实证分析

研究目的:确定住宅用地出让溢价率水平与宗地规模之间的关系,比较不同规模和区位城市中这一关系的差异。研究方法:理论分析,面板数据分析。研究结果:总体上宗地规模对土地溢价率的影响呈现"倒U"型变化关系,不同规模和区位城市中这一关系有差异。人口介于500万～1 000万之间的特大城市中土地溢价水平受宗地规模的影响较为强烈,东部和中部城市中宗地规模大小对土地溢价水平影响显著,西部城市不显著。研究结论:地方政府在总量既定条件下调整宗地投放规模可在一定程度上调控土地溢价率。     

Does bank capitalization matter for bank stock returns?

We examine US bank capitalization and its association with bank stock returns, and find that the book- and market-based capital ratios show different patterns. Fama-MacBeth regressions and portfolio analyses suggest that banks’ market-based capital ratios are negatively associated with banks’ stock returns during the (tranquil) 1994–2007 period while book-based capital ratios are positively associated with banks’ stock returns during the (turbulent) 2008–2014 period. These results suggest that the effect of bank capitalization on bank stock returns depends on the capital measure used and the period considered.     

货运车辆燃油消耗与运输效率关系研究

文中采用理论分析与模型构建相结合的方式,研究货运车辆的燃油消耗与运输效率之间的关系,基于调研数据,采用回归分析的方法构建模型,得到了不同车型车辆的百吨公里燃油消耗量与实载率的倒数关系模型,为企业提高车辆运输效率,降低燃油消耗提供数据参考。     

Impact of distance on the arrivals,behaviours and attitudes of international tourists in Hong Kong: A longitudinal approach

This study revisits the impact of distance on international tourist behaviours in Hong Kong. This work divides and cross-validates the concept of distance into physical and cultural distance. This work also proposes an alternative cultural distance measure by introducing optimal weight amongst Hofstede's dimensions and then compares the proposed measure with the traditional Kogut and Singh's and Kandogan's measures. By using data from the Visitor Profile Report of the Hong Kong Tourism Board and the World Trade Organisation from 2002 to 2017, along with latent growth curve modelling, multivariate regression and panel data analysis, findings confirmed the significant role of physical and cultural distance. In addition, quadratic relationships are detected using cross-validation methods. The effect of physical distance on tourist demands clearly dominates that of cultural distance in the overall market. The problem of spurious correlation and the results of three cultural distance measures are also discussed.     

On the predictability of the distribution of excess returns in currency markets

This paper investigates the predictability of foreign exchange (FX) volatility and liquidity risk factors on returns to the carry trade, an investment strategy that borrows in currencies with low interest rates and invests in currencies with high interest rates. Previous studies have suggested that this predictability could have been spuriously accounted for due to the persistence of the predictors. The analysis uses a predictive quantile regression model developed by Lee (2016) that allows for persistent predictors. We find that predictability changes remarkably across the entire distribution of currency excess returns. Predictability weakens substantially in the left tail once persistence is accounted for, implying a moderate negative predictive relation between FX volatility risk and carry trade returns. By contrast, it becomes stronger in the right tail. Furthermore, we provide evidence that FX volatility risk still dominates liquidity risk after controlling for persistence. These findings suggest that the persistence of the predictors needs to be taken into account when one measures predictability in currency markets. Finally, out-of-sample forecast performance is also presented.     

Exchange rate returns and volatility: the role of time-varying rare disaster risks

This paper provides empirical evidence to the theoretical claim that rare disaster risks have predictability for exchange rate returns and volatility using a nonparametric quantile-based methodology. Using dollar-based exchange rates for Brazil, Russia, India, China, and South Africa, the quantile-causality test shows that indeed rare disaster-risks affects both returns and volatility over the majority of their respective conditional distributions. In addition, these effects are much stronger when compared to those using the British pound, especially in terms of currency returns.