Welfare under friction and uncertainty: General equilibrium evaluation of temporary employment in the U.S.

Temporary contracts usually fall outside of employee protection litigation, thus they are often cheaper than permanent contracts and are offered on-demand by firms. In the last two decades, there has been a sharp growth in such contracts in the U.S. labor market. This paper investigates the welfare consequences of offering temporary contracts in the U.S., an environment with low employee protection litigation and high production risk for firms. Employee protection litigation creates firing rigidity in regular labor markets. Pairing firing rigidity with high production risk, firms reduce employment and output, which generates welfare loss. The inexpensive and flexible nature of temporary contracts offers firms a buffer strategy in making employment decisions under risk and navigating the firing rigidity of the regular labor sector, thereby reducing welfare loss. However, temporary contracts cannot fully compensate for the efficiency cost from rising firing rigidity and risk.     

Heterogeneous duopoly with isoelastic demand function

In this paper we analyze a duopolistic market with heterogeneous firms when the demand function is isoelastic (Puu, T., 1991. Chaos in duopoly pricing. Chaos, Solitons and Fractals 1, 573–581.). We consider the same heterogeneous firms of Zhang et al. (Zhang, J., Da, Q., Wang, Y., 2007. Analysis of nonlinear duopoly game with heterogeneous players. Economic Modelling 24, 138–148.) introducing a nonlinearity in the demand function instead of the cost function. Stability conditions of the Nash equilibrium and complex dynamics are studied. In particular we show two different routes to complicated dynamics: a cascade of flip bifurcations leading to periodic cycles (and chaos) and the Neimark-Sacker bifurcation which originates an attractive invariant closed curve. Comparisons with respect to the Puu model and the model of Zhang et al. are performed.     

"新新贸易理论"的思想脉络及其发展

新新贸易理论将企业异质性成功的引入到国际贸易模型中,从微观层面解释了贸易的发生及影响,从而开拓了国际贸易研究的新领域。新新贸易理论解释了为什么好的企业做国际贸易,而较次的企业做国内贸易这一现象,该理论认为,自由贸易可以提高产业生产率水平和社会福利,所以在政策上应该促进自由贸易而不是贸易保护。     

国外异质性厂商贸易理论研究综述

异质性厂商贸易理论代表了国际贸易理论最新发展趋势,研究的是微观经济主体--厂商的贸易和投资行为与自身特征的关系.厂商的市场进入方式与其生产率水平是相对应的,出口和贸易自由化能够提高行业生产率,汇率变化、贸易政策和产业集聚对厂商出口具有重要的影响,厂商进入出口市场前后存在自我选择效应和出口中学习效应,这两种效应都导致厂商生产率提高,最终生产率最高的厂商将以对外直接投资的方式进入国际市场.     

Similar patient outcomes yet different hospital costs between flowable hemostatic agents

Abstract

Introduction:

SURGIFLO? and FLOSEAL® are absorbable gelatin-based products that form hemostatic matrices. These products are indicated as adjuncts to hemostasis when control of bleeding by conventional surgical techniques (such as suture, ligature or cautery) is ineffective or impractical. This study analyzed the effect of surgery time and the choice of product on cost to the hospital and patient outcomes.     

A methodology for the construction of dynamic capabilities in industrial networks: The role of border agents

The article presents a methodology for the formation and functioning of industrial networks that favors the development of dynamic capabilities with regard to the creation, integration, transfer and absorption of knowledge. This methodology has been put into practice in a case study: Lignum Facile. The presence of some misalignments between our initial proposal and its implementation helped us reshape and emphasize particular processes and flows associated to the methodology. Beyond the typical localization and agglomeration advantages, the analysis suggests that the success in the formation and functioning of industrial networks is mainly related to their potential to formulate immaterial relationships capable of stimulating learning processes, the dissemination of technological knowledge and innovative activities. Particularly, we found that the inclusion of border agents – intermediaries between the market and industry such as architects, engineers or designers – is fundamental to develop innovations at the intersection of different scientific and technological disciplines.     

Do foreign exchange fund managers behave like heterogeneous agents?

This paper estimates an Heterogeneous Agent Model (HAM) on currency trader indices to explain the large shifts in profitability in currency styles surrounding the global financial crisis. In the model, fund managers allocate capital conditional on recent performance to a value strategy, a momentum strategy, and a carry strategy. Subsequent estimation results reveal that (1) a large part of the behavior of currency managers can indeed be described by these three simple strategies, and (2) currency managers shift capital from recent winning styles to recent losing styles, and hence apply a negative feedback strategy. We finally show that a negative feedback strategy is indeed optimal, but currency managers could improve performance by applying it less aggressively if they were able to.     

投资者异质后验信念对股票价格影响的实证研究

过度自信程度不同的投资者因消息确认精度差异引起意见分歧,产生异质后验信念,导致投资者对股价高估或者低估。在此基础上,以盈余公告信息作为利好或利空消息,研究不同环境下异质后验信念对我国股票价格的影响。实证结果表明:不管在牛市还是在熊市环境下,异质后验信念均会对股价产生影响,当盈余公告为利好消息时,异质后验信念程度越高,当期股价被高估的程度越显著;当盈余公告为利空消息时,异质后验信念程度越高,当期股价被低估的程度越显著。此外,在盈余公告前投资者就对盈余消息作出了反映,但对好消息与坏消息的反映程度不同。     

Which farmers benefit the most from Bt corn adoption? Estimating heterogeneity effects in the Philippines

The potential contributions of new biotechnologies to sustainable food and income security have been the subject of widespread discussions around the turn of the 21st century. But distributional issues of which segments of adopters of genetically modified (GM) crops benefit the most have not been given ample attention). Using propensity scores, we apply the (a) stratification‐multilevel method of estimating heterogeneous treatment effects; and the (b) matching‐smoothing method of estimating heterogeneous treatment effects proposed by Xie et al. We find that the incidence of higher yields, lower insecticide use, and reduced seed utilization in the Philippines diminishes progressively as a farmer's propensity to adopt Bt corn increases. Farmers with a low propensity to adopt Bt are those who farm smaller, nonirrigated farms located farther from seed suppliers and farmers without previous training on pest identification. In most cases, while these farmers are typically poorer farmers in smaller parcels, cannot afford irrigation and are situated in remote areas away from easily accessible seed suppliers, there is no evidence, however, that profits differ across farmers with varying propensities to adopt the Bt variety.     

基于产出冲击的国际储备需求的跨期均衡分析——真实经济的视角

与现有研究相比,文章从真实经济的角度构造了一个简单的基于代表行为人的跨期均衡模型,探讨基于产出冲击和消费平滑的主动性储备需求的决定。研究表明:主动性储备需求与产出冲击发生的概率、产出冲击大小、代表行为人的相对风险厌恶系数以及代表行为人的主观贴现率呈正向关系,与经济增长速度呈反向关系,而与储备资产的相对价格呈现出非线性的关系。通过数值模拟发现,我国主动性储备约占2007年GDP的6%(相当于我国2007年底国际储备的12%),说明我国近年来增加的国际储备存在较大的被动持有部分,目前的国际储备持有额已经从一定程度上脱离了实体经济的基本需求。因此,除紧缩的货币政策外,我国政府还需要进一步运用汇率政策、贸易政策以及其他干预政策直接降低被动国际储备额。