Bancarization and violent attacks from guerrilla and other illegal groups in Colombia

Income shocks affect violence through the opportunity cost and rapacity effects. Existing studies focus on the impact of transitory shocks, especially commodity price innovations. This paper builds on this literature and studies the causal effect of permanent income shocks on armed conflict in Colombia. Using a rich dataset reporting all guerrilla and other armed groups' attacks by municipality between 2009 and 2014 and information on the provision of banking services, it shows that increasing bancarization leads to reductions in violence. These results have important implications for public policy in countries with a long history of violence. They suggest that promoting financial inclusion is useful for reducing conflict.     

探究“新零销售”模式下影响销售量的相关因素

在新零销售模式的推动下,客户越来越倾向于消费个性化的商品。为了精准预测客户的消费需求,论文以单款单色产品为研究对象,通过建立多元回归分析的数学模型,来探究影响商品销售量的相关因素。经过分析发现,除了一些定性因素外,定量因素对销售量也产生了一定的影响,其中实际花费总金额、实际销售单价、库存数等定量因素对销售量的影响较大,且各个变量之间具有相关性,所以电商平台应特别关注这三个变量的影响。     

地区间产业融合有利于缩小区域经济差异吗？——兼析中国地区间产业融合网络及其结构演变

区域发展不平衡的问题需要通过加强地区间的经济联系来解决,地区间的产业融合在发挥各地区比较优势促进整体经济发展的同时,也会通过一体化的产业体系促进区域经济差异的缩小。基于中间品投入产出关系设计地区间产业融合水平评价指标,并采用2002年、2007年和2012年《中国区域间投入产出表》的数据,以30个省级区域为地区单元构建地区间产业融合网络,分析表明：在样本期间,中国的地区间产业融合网络格局处于动态演进中,在总体水平显著提高的同时也存在地区发展的不平衡,部分地区与其他地区的产业融合水平有待提升;中国的地区间产业融合网络具有与地理位置相关的板块特征,地理因素对地区间产业融合具有重要影响。进一步运用QAP回归方法分析地区间产业融合水平变化对经济发展水平差异变化的影响,结果表明地区间产业融合水平的提升有利于区域经济差异的缩小。因此,应积极深化社会主义市场经济体制改革,促进地区间市场和产业的一体化发展,并通过加快数字经济发展和基础设施建设等弱化地理因素对地区间产业融合的制约,进而提升地区间产业融合水平并优化其网络结构;在提高地区间产业融合发展水平的同时,也要积极缩小地区间资本积累、产业结构等方面的差异,以更有效地促进区域经济差异缩小。     

旅游城市财政收入与GDP关系的实证研究

财政收入和GDP是众多经济指标中的关键指标,研究旅游城市中两者的相互关系并加以利用,有利于旅游城市经济的可持续发展。研究表明,作为全国著名的旅游城市桂林地方财政收入与GDP存在显著的线性关系,财政收入稳定性较高,但地方财政收入占GDP的比重低于广西全区平均水平及区内部分市水平,财源亟待培育。     

Location determinants of high-growth firms

County-level location patterns of INC5000 companies provide one map of American entrepreneurship and innovativeness, and understanding the local factors associated with these firms’ emergence is important for stimulating regional economic growth and innovation. We draw on the knowledge spillover theory of entrepreneurship to motivate our regression model, and augment this theory with additional regional features that have been found to be important in the firm location literature. Zero-inflated negative binomial regressions indicate that these firms exist in counties with larger average establishment size, higher educational attainment and more natural amenities. Income growth, a mix of higher paying industries, and more banks per capita are associated with a smaller presence of these types of firms, all else equal. We conclude that the local conditions favouring high-growth firms are likely to be different from those favouring new firms in general, and that these conditions differ significantly in urban and rural areas and by industrial sectors.     

Calibration Weighting Methods for Complex Surveys

This paper presents a careful investigation of the three popular calibration weighting methods: (i) generalised regression; (ii) generalised exponential tilting and (iii) generalised pseudo empirical likelihood, with a major focus on computational aspects of the methods and some empirical evidences on calibrated weights. We also propose a simple weight trimming method for range‐restricted calibration. The finite sample behaviour of the weights obtained by the three calibration weighting methods and the effectiveness of the proposed weight trimming method are examined through limited simulation studies.     

On new variance approximations for linear models with inequality constraints

In this paper, we examine the estimation of linear models subject to inequality constraints with a special focus on new variance approximations for the estimated parameters. For models with one inequality restriction, the proposed variance formulas are exact. The variance approximations proposed in this paper can be used in regression analysis, Kalman filtering, and balancing national accounts, when inequality constraints are to be incorporated in the estimation procedure.     

货币政策影响居民储蓄行为的有效性分析

本选取了我国1994年至2000年的统计数据，通过统计学的方法来分析货币政策在分流我国居民的巨额储蓄时是否有效，并进一步分析了对货币政策效果产生干扰的制度因素。     

Cross Validation Calibration Based Shrinkage – Revisited for the Construction of Prognostic Indices

The use of shrinkage methods for the construction of prognostic indices has been paid increasing attention in the literature on medical statistics in the last years. One approach for the construction of a shrinkage factor is cross validation calibration as suggested by van H ouwelingen and le C essie (1990). We investigate this approach in more detail. First we try to clarify why shrinkage factors constructed by cross validation calibration tend to be smaller than 1. Second we explain why use of this shrinkage factor can result in an improvement of the average prediction error. Third we investigate the possible gain for constellations relevant in medical research by means of a simulation study, focusing on the dilemma, that the improvement on average has to be paid by distinct deteriorations for some patients. Finally we conclude that it is necessary to rethink the choice of loss functions in constructing prognostic indices before recommendations about the use of shrinkage methods can be made.     

回归分析在土地估价中的应用

回归分析是一种统计学方法，在地价分析与测算中得到广泛应用。本文从统计学的角度阐明了回归分析的原理，并介绍了如何建立回归方程解决土地估价中出现的有关问题。