医疗保险与城乡反贫困:1989-2006

文章利用中国健康与营养调查(CHNS)数据,估计了1989-2006年医疗保险对中国城乡家庭的反贫困效应。结果发现:发生灾难性卫生支出的城乡家庭比例较高,最穷的群体其医疗费用超过收入的比例增加,医疗保险对减少收入不平等只起到微弱作用。TIP贫困曲线表明,近几年,医疗保险补偿后,城乡患病家庭的贫困并没有减轻,医疗保险在减少贫困上的作用很小。分析贫困特征的多元回归模型显示,家庭成员数量、教育程度、抚养比率、参保人数等都影响了贫困,而条件多元回归模型则显示,医疗保险对贫困的变动没有影响。     

Estimated Open Economy New Keynesian Phillips Curves for the G7

In this paper we develop an open economy model of firms’ pricing behaviour under imperfect competition. This allows us to introduce various terms of trade effects influencing the firm’s pricing decision, in addition to labour costs which dominate most closed-economy specifications of the New Keynesian Phillips curve (NKPC). Our analysis gives rise to a hybrid open economy NKPC which nests existing closed and open economy specifications adopted in empirical work. We estimate this specification for the G7 economies and find that the US, UK and Canada typically enjoy less inertia in price setting than the European G7 economies and Japan and that these estimates are both plausible and in line with survey evidence. We also find that the proportion of firms which use simple backward-looking rules of thumb in price setting is greater when the frequency of price change is smaller. Finally there is evidence of significant asymmetries in price setting amongst EMU members.

Phillips curve in US: New insights in time and frequency

The paper explores the co-movement between unemployment and inflation rates in US by using a battery of wavelet tools. The dataset covers the period 1945Q1–2017Q4, having quarterly frequency.The main findings reveal a not stable Phillips curve in US, depending on economic context, seasonality and time-persistence. The Phillips curve is not validated during economic turbulences, while it works over expansion economic periods. Even so, the trade-off between unemployment and inflation is unstable under seasonal growth components and time-persistence, running from short- to medium-term. No link between unemployment and inflation is found in the long-term.     

基于改进F-N曲线的滑坡可接受风险水平研究

滑坡灾害的可接受风险水平是滑坡领域的重要研究内容之一,它常常用F-N曲线直观地表示风险频率与后果之间的关系,然而这种传统方法的参数由人为确定,主观性强,缺乏理论依据,且同一个参数不能适用多个地区和风险.以滑坡灾害的相关规范为依据,用风险矩阵的方法做衔接,绘制出3种决策态度下的滑坡灾害可接受风险的F-N曲线.相比传统的方法,改进后的F-N曲线避免了以上缺陷,使得滑坡灾害可接受风险水平的确定更加精准,同时该方法也可运用到其他领域的相关规范,来研究其可接受风险水平.     

人民币汇率波动与我国通胀、产出波动：一个扩展泰勒曲线的研究

发挥市场供求对汇率的调节作用,增强人民币汇率双向浮动弹性,是当前我国汇率体制改革的主要方向。本文在泰勒曲线的框架下考察人民币汇率波动对我国宏观经济波动和货币政策实施的影响。通过实证研究发现,1994—2006年通货膨胀波动对人民币汇率波动是不敏感的,人民币汇率传递效应不显著,人民币汇率波动对宏观经济波动没有显著的影响;2007年以后人民币汇率波动推动泰勒曲线向内移动,因此更大的人民币汇率弹性对货币政策传导和货币政策有效性是有利的,逐步扩大的人民币汇率弹性区间对我国宏观经济运行是适宜和可接受的。另外人民币汇率波动也使得泰勒曲线更加陡峭,稳定通货膨胀所导致的产出缺口波动减小了,因而更有利于货币政策当局追求一个低而稳定的通胀目标。     

气体涡轮流量计K-q_v曲线特性研究

通过对1台DN80气体涡轮流量计在1m3/h~1.5qmax流量范围内进行实验,得出气体涡轮流量计的仪表系数K与流量qv之间的特性曲线,表明在0.8qmin以下仪表系数不稳定,流量计超差;在qmax~1.5qmax范围内仪表系数稳定性最好,流量计准确度最高。由此说明实验所选型号的气体涡轮流量计,仪表系数在标称流量范围以外仍有可能满足计量要求,特别是大于标称流量上限后仪表系数仍然稳定,在学术研究领域扩展了思路,也为选型应用提供了借鉴的经验。     

用聚类分析方法划分孔隙结构类型及其验证

基于SPSS软件的聚类分析模块将研究区的储层孔隙结构划分为I型、II型、III型、IV型4个类型,从I型到Ⅳ型孔隙结构逐渐变差,并运用毛管压力曲线对划分的合理性进行验证。验证结果表明:各类型的储层孔隙结构之间差异较明显,划分界限清晰,可以指导储层分类开发。     

LS曲线拟合下的时差估计

针对时差估计（TDE）易受噪声影响产生模糊的问题,推导了单频信号、线性调频（LFM）信号以及二进制相移键控（BPSK）信号的互相关（CC）函数表达式,以最小二乘（LS）曲线拟合细化CC函数的幅度谱,获取精确的时差估计。首先对CC函数的幅度谱进行谱峰搜索,得到时差的粗估计,然后对CC函数的幅度谱以时差的粗估计为界,根据脉内调制类型,选择相应的一次或二次曲线,进行LS曲线拟合,降低噪声项对信号项的影响,可有效排除伪峰和局部最大,获得时差的精确估计。仿真结果显示,在信噪比大于6 dB时,BPSK信号的时差估计均方根误差接近零。     

Is research on marginal lands catching up? The case of unfavourable wheat growing environments⋆

It is widely believed that the Green Revolution had very little effect in unfavourable or marginal environments. Many researchers have been concerned about the slow progress of technical change in marginal environments and the level of research resources allocated to these areas. This paper provides empirical evidence that there has been significant growth in wheat yield potential in marginal environments, especially during the post‐Green Revolution. International yield trial data, covering all major wheat growing environments from 1964 to 1999, were used in estimating the growth in wheat yield potential and changes in yield variability. The global database on wheat varietal adoption and yield gains based on estimated wheat yield growth rates were used to determine production increases due to wheat breeding research. Results show greater progress in shifting the wheat yield frontier in marginal areas, particularly in drought and high temperature environments. Furthermore, yield variability in marginal environments has notably declined, while it has increased slightly in favourable environments. While initial gains came from crossover of varieties from favourable environments, targeted breeding efforts have contributed significantly to more recent productivity growth in marginal environments. Increased production from marginal environments accounted for around 25% of the total wheat production increase in 1997. These findings show greater progress in wheat research and the huge potential of improving wheat productivity in unfavourable environments.     

基于吉尼系数原理的森林资源分布非均衡性评价模型与实证研究

将西方经济学原理与中国国情、林情结合,建立了森林资源分布非均衡性评价的一般模型。实证研究发现,在第四次、第五次森林清查期间,我国森林资源的吉尼系数均大大超过世界公认的吉尼系数警戒线,已达到两极分化线,并且森林资源洛伦斯曲线有弯曲程度加大的趋势。表明在此期间虽然森林覆盖率显著提高,但森林分布不均衡特征显著恶化,部分区域生态环境仍相当脆弱。建议坚持科学发展观,将改善森林资源分布相对均衡性要求纳入我国林业战略规划。