Earnings Instability and Tenure

We study the effect of tenure on earnings instability in Italy using the reforms of temporary employment contracts, which affected the average tenure of workers differentially across cohorts. We develop a model of earnings dynamics, and we exploit the variation of tenure and instability over time and across birth cohorts to estimate policy‐relevant parameters. Our results indicate that each year of tenure on the job reduces earnings instability by 11 percent; the drop is faster in the first three years of the match. Workers on a temporary contract have an earnings instability up to 100 percent higher than workers on a permanent contract.     

基于SD模型的诸城市农业结构仿真优化研究

［目的］预测2017—2035年诸城市农业结构的变化趋势，对农业结构进行多情景优化仿真，提出优化调整建议。［方法］文章以山东省诸城市作为研究对象，将农业结构划分为种植、种养结合和加工休闲3个子系统，选取56个指标，运用多元统计回归分析等方法构建41个方程，建立农业结构系统动力学（System Dynamics，简称SD）模型，运用Vensim—PLE软件进行仿真优化分析。［结果］SD模型预测结果表明，到2035年，粮食作物播种面积1105万hm2，总产量8037万t，经济作物播种面积652万hm2，总产量15203万t； 生猪出栏量达到29615万头，家禽出栏量1105 231亿只，畜禽粪污利用率8792%； 农业总产值达到25132亿元，休闲农业产值6134亿元，食品加工业产值1 25263亿元。假设种植业生产中的农业科技投入增加2个百分点， 2035年粮食作物产量较优化前增加576万t； 经济作物产量较优化前增加2814万t； 假设有机肥施用补贴增加3个百分点， 2035年畜禽粪污利用率较优化前提高762个百分点； 假设农产品加工业的研发力度和科技投入增加1个百分点， 2035年食品加工产值较优化前增加73521亿元； 农产品加工业产值占农业总产值比值由优化前的325：1达到41：1。［结论］为进一步推进诸城市农业结构调整，迫切需要加大农业科技投入，完善有机肥扶持政策，培育种养结合新型经营主体，重点扶持培育加工龙头企业，发展现代化休闲农场，促进农业产业融合发展。     

高校研究生导师学术休假制度刍议

文章对建立导师学术休假的必要性以及我国导师学术休假的现状作了分析,重点介绍了构建导师学术休假制度的实施策略,总结了为建立具有中国大学特色的学术休假制度而需逐步营造的导师学术休假的政策环境。     

梅州市现阶段开展校园足球的现状与分析

梅州市是我国足球后备人才培养重要城市,校园足球在梅州市小学的开展情况具有极强的代表性与研究价值,本文通过问卷调查广泛了解校园足球开展的现状,分析影响校园足球开展的主要因素。为校园足球活动今后在梅州市乃至全国的开展提供理论依据。     

Firm resources,competitive actions and performance: investigating a mediated model with evidence from the in‐vitro diagnostics industry

Building on the resource‐based view (RBV) and competitive dynamics literatures, this paper proposes that considering resources or actions independently offers an incomplete understanding of the drivers of superior performance. Instead, we hypothesize that resources enable competitive actions and that when these actions leverage the firm's resources, superior performance results. We tested these hypotheses with panelized data on the technological resources and competitive actions of firms in the in‐vitro medical diagnostic substance manufacturing industry. The results provide substantial support for our hypotheses, specifically with respect to mediation. Our theory and results underscore how the integration of the competitive dynamics and RBV literatures can significantly improve our understanding of firm performance. Copyright © 2011 John Wiley & Sons, Ltd.     

Does Money Matter in Shaping Domestic Business Cycles? An International Investigation

We study the contribution of money to business‐cycle fluctuations in the United States, the United Kingdom, Japan, and the euro area using a small‐scale structural monetary business cycle model. Constrained likelihood‐based estimates of the parameters are provided and time instabilities analyzed. Real balances are statistically important for output and inflation fluctuations. Their contribution changes over time. Models giving money no role provide a distorted representation of the sources of cyclical fluctuations, of the transmission of shocks, and of the events of the last 40 years.     

Escape dynamics: A continuous-time approximation

We extend a continuous-time approximation approach to the analysis of escape dynamics in economic models with constant gain adaptive learning. This approach is based on the application of the results of continuous-time version of large deviations theory to the linear diffusion approximation of the original discrete-time dynamics under learning. We characterize escape dynamics by analytically deriving the most probable escape point and mean escape time. The approximation is tested on the Phelps problem of a government controlling inflation while adaptively learning a misspecified Phillips curve, studied previously by Sargent (1999) and Cho et al. (2002) (henceforth, CWS), among others. We compare our results with simulations extended to very low values of the constant gain and show that, for the lowest gains, our approach approximates simulations relatively well. We express reservations regarding the applicability of any approach based on large deviations theory to characterizing escape dynamics for economically plausible values of constant gain in the model of CWS when escapes are not rare. We show that for these values of the gain it is possible to derive first passage times for learning dynamics reduced to one dimension without resort to large deviations theory. This procedure delivers mean escape time results that fit the simulations closely. We explain inapplicability of large deviations theory by insufficient averaging near the point of self-confirming equilibrium for relatively large gains which makes escapes relatively frequent, suggest the changes which might help approaches based on the theory to work better in this gain interval, and describe a simple heuristic method for determining the range of constant gain values for which large deviations theory could be applicable.     

Positive welfare effects of trade barriers in a dynamic partial equilibrium model

We develop a simple two-region, cobweb-type dynamic partial equilibrium model to demonstrate the existence of optimal, possibly non-zero, trade barriers. A pure comparative statics analysis of our model suggests that a reduction of trade barriers, modeled as small but positive import tariffs, always enhances welfare. However, taking a dynamic perspective reveals that nonlinear trade interactions between two regions may generate endogenous price fluctuations which can hamper welfare. Finally, we allow special interest groups, such as consumers or producers from these two regions, to lobby for a particular level of trade barriers. Our model predicts that time-varying trade barriers may be another channel for market instability.     

常州智慧旅游发展情况分析及相关建议

智慧旅游作为一个全新的研究课题,各城市在此方面不断地进行探索与实践。文章采用实地访谈与体验、网络调查、文献检索等方法,对常州智慧旅游相关的行业、企业、事业单位进行了调查,就其发展现状和存在不足进行了分析,并提出了相应的发展建议。     

Global and Euro Imbalances： China and Germany

We analyze global and euro area imbalances by focusing on China and Germany as large surplus and creditor countries. In the 2000s, domestic reforms expanded the effective labor force, restrained wages, shifted income toward profits and increased corporate saving. As a result, the Chinese and German current account surpluses widened, and that of Germany has proven more persistent, with subdued domestic investment. China is an early-stage creditor, holding a short equity position and a longposition in safe debt. Germany＇s balanced net debt and equity claims mark it as a mature creditor thatprovides insurance to the rest of the world. China pays to lay off equity risk, while Germany, by contrast, harvests a moderate yield on its net claims. In both economies, the shortfall of the net international investment position from cumulated current account surpluses arises from exchange rate changes, asymmetric valuation gains, and, in Germany＇s case, credit losses.