The Impact of Omitting Promotion Variables on Simulation Experiments

Using store-level scanner data, elasticity matrices are estimated using a twotiered demand system. Two basic models are estimated, one with promotion variables and one without. Differences between the estimates across the two models are statistically significant. However, when the elasticities are used as 'inputs' into several simulation exercises, there are only small differences in merger effects and patent damage estimates.The results suggest that the differences are not 'economically' significant.     

Intersectoral wage linkages: the case of Sweden

The purpose of this study is to investigate whether wage-setting in certain sectors of the Swedish economy affects wage-setting in other sectors. The theoretical background is the Scandinavian model of inflation, which states that wage-setting in the sectors exposed to international competition lead wage-setting in the sheltered sectors of the economy. The Johansen maximum likelihood cointegration approach is applied to quarterly data on Swedish sector wages for the period 1980:1–2002:2. Different vector error correction (VEC) models are created, based on assumptions as to which sectors are exposed to international competition and which are not. Granger causality tests are then carried out in the different restricted/unrestricted VEC models to test for sector wage leadership. The Granger causality tests provide strong evidence for the presence of intersectoral wage causality, but no evidence of a wage-leading role for the internationally exposed manufacturing sector.      

中部地区固定资产投资与经济增长关系的实证分析——以阜阳市为例

本文对阜阳市固定资产投资与经济增长之间的关系进行了定量分析,通过建立误差修正模型来反映二者之间长期均衡和短期波动关系,分析固定资产投资对当地经济增长的贡献水平,结果表明固定资产投资能有效的拉动当地经济增长。     

Environmental regulation and trade pattern：a case of China

As a growing number of countries, including both developed and developing countries, have in recent yearstaken environmental regulation at different levels, a question of great concern has been raised： can the regulation alterthe existing trade volume and trade pattern, and ultimately drive pollution-intensive industries to countries with low-levelregulations or even those without regulations at all？ Starting from the three different propositions concerning therelationship between environmental regulation and trade pattern, this paper applies cointegration analysis and errorcorrection model to empirically testing the relationship between environmental regulation and trade in China during theperiod of 1985-2005. Our empirical results indicate that in the short run the collection of pollution discharge fees bearsa positive impact on the export share of clean products of total exports. Thus, higher pollution discharge fees raise theratio of clean products exports to total exports. This further indicates that more stringent environmental regulationpromotes the exports of clean products. In the long run pollution discharge fees are positively correlated with the exportshare of clean products but negatively associated with their import share. Such correlations imply that environmentalregulation tends to facilitate the international specialization in line with comparative advantages.     

FDI与湖南产业结构关系的实证研究

对湖南的产业结构和三次产业利用FDI的现状进行了分析,利用1983～2006年的统计数据,运用协整分析技术、误差修正模型和Cranger因果关系检验,对FDI与产业结构变动之间的关系进行了实证研究.结果表明,FDI与产业结构变动之间存在正向的协整关系,FDI是产业结构变动的重要原因;在短期FDI偏离了产业结构的长期均衡水平,但短期波动对长期均衡的回调速度较快.进而,就模型得出的结论提出了若干建议.     

Limits to forecasting in personalized medicine: An overview

Biomedical research is generating massive amounts of information about potential prognostic factors for health and disease. However, few prognostic factors or systems are robustly validated, and still fewer have made a convincing difference in health outcomes or in prolonging life expectancy. For most diseases and outcomes, a considerable component of the prognostic variance remains unknown, and may remain so for the foreseeable future. I discuss here some of the main problems in medical forecasting that pose obstacles to personalized medicine. Their recognition may help identify solutions to improve personalized prognosis, or at least understand and cope with the component of the future that we cannot predict. Much prognostic research is stuck at generating “publishable units”, without any interest in conclusively proving their worth, let alone moving them into real life applications. Information is reported selectively and reporting is deficient. The replication record of prognostic claims is poor. Even among replicated prognostic effects, few are convincingly shown to add much information besides what is already known through more simple, traditional measurements. There are few efforts to systematize prognostic knowledge. Most prognostic effects are subtle when traced to the molecular level, where most current research operates. Many researchers, clinicians, and the public are not appropriately educated to interpret prognostic information. We still have not even agreed on what the important health outcomes are that we want to predict and intervene for, and some subjectivity may be unavoidable. Finally, without concomitant effective, affordable, and non-harmful interventions, prognosis alone is of questionable value, and wrong prognosis or a wrong interpretation thereof can be harmful. The identification of these problems also suggests a roadmap on what could be done to amend them. Solutions include a systematic approach to the design, conduct, reporting, replication, and clinical translation of prognostic research; as well as the education of researchers, clinicians, and the general public. Finally, we need to recognize that perfect individualized health forecasting is not a realistic target in the foreseeable future, and we have to live with considerable residual uncertainty.     

一种无人值守接力的靶场安控系统

本文论述了中国实行对外开放是邓小平和中国人民把握历史和时代发展规律作出的战略抉择并取得了巨大成就;分析总结了中国入世前对外开放的基本特征及其原因;重点探讨了中国入世后对外开放的新阶段、新特点及其应对措施,推动对外开放新阶段和开放型经济新发展。     

一种实用的无线信道纠错方法

核心竞争力是企业适应市场的潜力。中国某些企业由于缺乏核心竞争力而使其市场份额逐渐缩小。为了适应国际市场竞争的形势,发展企业核心竞争力是重中之重。为此,除了企业加强自身建设以外,政府应该利用法律和政策,充分利用加入WTO以后宝贵的“缓冲期”,使国内市场尽快完善,促进企业核心竞争力的不断提高。     

Distributional effects of environmental taxes on transportation: evidence from Engel curves in the United States

Indirect taxes on transportation activities that pollute can correct externalities and close the gaps between private and social costs. However, policy makers often find such Pigou taxes difficult to implement because of political resistance due to possibly adverse affects on equity. For this reason it is important to assess the distributional aspects of environmental levies. This article estimates properties of the demand for transportation in parametric and non-parametric analyses of Consumer Expenditure Surveys for the United States and finds patterns in the resulting set of Engel curves. Private transportation using air flights and new cars has Engel elasticity above unity while public transportation via mass transit has Engel elasticity below unity. The findings can be interpreted in an important way since they show that a differentiated scheme of environmental taxes on transportation may function progressively. A Pigou scheme with larger taxes on modes of transportation that pollute more appears to coincide with larger levies on luxury modes preferred by richer households.     

Spurious welfare reversals in international business cycle models

Several papers have documented spurious welfare reversals: incomplete-markets economy produces a higher level of welfare than the complete-markets economy. This paper first demonstrates how conventional linearization can generate approximation errors that can result in welfare reversals. Using a two-country production economy, we argue that spurious welfare reversals are not only possible but also plausible under reasonable values for model parameters. This paper then proposes an approximation method that modifies the conventional linearization by a bias correction. This method can be easily implemented and approximates welfare as accurately as a second-order perturbation method.