A political economy perspective on horizontal FDI in a dynamic Cournot-oligopoly with endogenous entry

Entry in a homogeneous Cournot-oligopoly is excessive if and only if there is business-stealing (Amir et al., 2014). The excessive entry prediction has been derived primarily for closed economies and using a welfarist benchmark. We extend this framework and allow for (1) horizontal FDI in a multi-period setting and (2) interest group-based government behaviour. Opening the market to greenfield investments from abroad tends to aggravate the entry distortion. Moreover, market opening may reduce welfare if a more pronounced entry distortion dominates the gain in consumer surplus. Finally, a government, which places sufficiently little weight on the interests of consumers, will object to market opening, even if welfare rises.     

Asymmetry,Complementarities, and State Dependence in Federal Reserve Forecasts

Forecasts are a central component of policymaking; the Federal Reserve's forecasts are published in a document called the Greenbook. Previous studies of the Greenbook's inflation forecasts have found them to be rationalizable but asymmetric if considering particular subperiods, for example, before and after the Volcker appointment. In these papers, forecasts are analyzed in isolation, assuming policymakers value them independently. We analyze the Greenbook forecasts in a framework in which the forecast errors for different variables are allowed to interact. We find that allowing the losses to interact makes the unemployment forecasts virtually symmetric, the output forecasts symmetric prior to the Volcker appointment, and the inflation forecasts symmetric after the onset of the Great Moderation.     

基于SFA模型的河南省粮食产量时空变化及投入要素影响

[目的]粮食问题影响着一个国家的国民经济发展和人民生产、生活,农业在整个社会生产活动中占有重要地位,河南省是全国农业大省,对河南省粮食产量进行分析具有重要的现实意义。[方法]以2005—2015年河南省各县粮食产量和投入要素为研究对象,将研究数据面板化,利用线性相关、随机前沿生产函数模型、脱钩分析等方法,运用ArcGIS 10.1、Eviews 8.0和SPSS 19.0等软件,对河南省各县粮食产量时空变化、投入要素影响程度和脱钩效应进行分析。[结果]模型运算结果表明文章选用模型效果较好,能够反映粮食产量的时空变化以及其与投入要素之间的关系,且符合河南省粮食产量实际情况。研究结果表明:(1)从时间上来看, 2005—2015年河南省粮食产量总体呈线性上升趋势;(2)从空间上来看,河南省中部、北部、东部和南部粮食产量较高,西部受地势因素影响粮食产量较低;(3)粮食产量与化肥施用折纯量、粮食播种面积、农民经营性收入、农药施用量、农业机械总动力和乡村农业人口呈正相关关系,与农村用电量呈负相关关系;(4)化肥施用折纯量、农村用电量、农药施用量存在脱钩效应,粮食播种面积、农民经营性收入、农业机械总动力不存在脱钩效应。[结论]应保持目前粮食播种面积不变,提高农业机械总动力,突出投入要素的影响,同时对河南省各县进行区域功能定位。     

On Some Characteristics of Gaussian Covariance Functions

The concepts of isotropy/anisotropy and separability/non‐separability of a covariance function are strictly related. If a covariance function is separable, it cannot be isotropic or geometrically anisotropic, except for the Gaussian covariance function, which is the only model both separable and isotropic. In this paper, some interesting results concerning the Gaussian covariance model and its properties related to isotropy and separability are given, and moreover, some examples are provided. Finally, a discussion on asymmetric models, with Gaussian marginals, is furnished and the strictly positive definiteness condition is discussed.     

Estimating input-mix efficiency in a parametric framework: application to state-level agricultural data for the United States

ABSTRACT

This paper contributes to the productivity literature by demonstrating novel econometric methods to estimate input-mix efficiency (IME) in a parametric framework. Input-mix efficiency is defined as the potential improvement in productivity with change in input mix. Any change in input-mix (e.g., land to labou r ratio) will result in change in productivity. The advantage of this approach is that it does not require data on input prices to estimate the mix efficiency levels. A nonlinear input-aggregator function (e.g., Constant Elasticity of Substitution) is used to derive an expression for input-mix efficiency. Bayesian stochastic frontier is estimated for obtaining mix efficiency using US state-level agricultural data for the period 1960–2004. Significant variation in input-mix efficiency is noted across the states and regions, attributable to diverse topographic and geographic conditions. Furthermore, comparisons of allocative and mix efficiencies provide insightful policy implications. The production incentives such as taxes and subsidies could help farmers in adjusting their input mix in response to changes in input prices, which can affect the US agricultural productivity significantly. The proposed methodology can be extended by i) using flexible functional forms; ii) introducing various time- and region-varying input aggregators; and iii) defining more sophisticated weights for input aggregators.     

Is heterogeneous capital depreciation important for estimating firm-level productivity? Evidence from Chinese manufacturing firms

This paper contributes to the existing literature on estimating firm-level production functions. Using Chinese manufacturing survey data, we employ the firm-level heterogeneous capital depreciation rate to measure firms’ investment and assess its role using Olley and Pakes (1996) (OP) production function estimation technique. Although there is some ongoing debate on the econometric soundness of the OP technique, we argue quantitatively that the heterogeneous depreciation rate muffles the measurement error associated with the key input demand investment. In our sample, it significantly narrows the gap of total factor productivity (TFP) estimates between the OP technique and a state-of-the-art estimation method that works without investment. We further reveal that the improved performance primarily originates from the dynamic evolution in the distribution of the capital depreciation rate.     

一种机载三维音频技术的快速计算方法

针对机载三维音频应用的实时性需求，提出了一种基于单耳相对头相关传递函数和改进型混响模型的机载三维音频快速实现方法，在较传统实现方式性能无明显下降的情况下降低了80%的计算量。对提出的算法在F-16战斗机模拟强噪声环境下进行相关主观试听实验，同时在某型飞机音频系统中实验验证。实验结果表明,所提方法在实时处理3路三维音频时，三维音频方位分辨精度在5°以内，可满足实际机载平台使用需求。     

探析横管式煤气初冷器阻力大的原因及应对措施

在焦化行业内,炼焦过程必将产生大量焦炉荒煤气,采用煤气鼓风对焦炉荒煤气进行处理就成为工作重点,不仅能够促进环境的改善,还可以回收荒煤气中大量的化工原材料,并带来较大的经济效益。但在焦化厂实际生产中,横管式煤气初冷器常常因阻力过高发生故障,对煤气鼓风机的正常运作形成干扰,造成装置沉积物阻塞与环境污染等问题。论文以湖北中平鄂钢联合焦化有限责任公司的横管式煤气初冷器为实例,简要分析阻力增大的原因及应对措施。     

农网改造升级工程接地施工若干质量问题的防控探讨

当前我国已经将决战脱贫攻坚、决胜全面建成小康社会作为主要的战略目标,为了实现这一目标,实现脱贫攻坚,电力保障是一个非常重要的因素。近年来我国全面推进农网改造升级工程。农网改造工程的接地施工质量的重要性毋庸置疑,但是农网改造工程的特殊性又使得接地质量的判断变得不好把握,本文从农网改造工程接地质量现状、防控措施等方面进行探讨。     

Productivity impact of drought tolerant maize varieties under rainfall stress in Malawi: A continuous treatment approach

Drought tolerant (DT) maize varieties have received massive support in sub‐Saharan Africa because of their potential to protect smallholder farmers against drought‐related maize yield losses. Using four waves of household farm panel data from six districts in Malawi, we examine the impact heterogeneity of this technology on maize productivity using a continuous treatment approach. We find strong evidence of positive correlation between maize yield and adoption of DT maize varieties. On average, an increase by one hectare in the area allocated to DT varieties increases maize yield by 547 Kg/ha representing a 44% increase from the average maize yield of 1,254 Kg/ha for our sample. Our findings give evidence that DT maize technology has potential to protect smallholder farmers against drought‐related production losses. Policies that promote increased allocation of maize area to DT maize hold potential to enhance food security. Smallholder farmers especially in drought‐prone areas should be encouraged to allocate at least one‐third of the maize plot to DT varieties while breeders continue with the efforts of breeding a DT variety that is not only drought tolerant but also adapted to all weather conditions. More importantly, the government should ensure provision of timely ex ante weather information to guide farmers on decision‐making with respect to maize varietal choices.