The future of the mobile phone business

One of the fastest growing technologies of our times is that of mobile phones. In this article we use the assumption that the diffusion of mobile technology, as measured by the number of active mobile accounts, follows the well known S-curve of natural growth in competition systems. The accuracy of the logistic fit is tested against actual data for the whole world, Europe, China and the GSM system. Using the produced models predictions concerning the future of mobile business are deliberated.According to these models active mobile accounts around the globe are expected to grow from 1.7 billion in 2004 to approximately 2 billion in 2008, reaching a peak penetration of 29.2%. Growth barriers, apart from the age of the potential user, are also low income and extreme poverty. Europe, early adopter of mobile technology and leader in active mobile accounts against all other regions in the world, has apparently reached a peak with almost every European, apart from the very young or very old, using a mobile phone. The mobile market in China is anticipated to exceed 500 million active accounts and may increase even further depending on the economic and social reform that is currently under way in that part of the world. GSM will most likely remain the leading mobile technology in the future as it is today.The growth process for the world, Europe, and the GSM system is almost completed and during this stage instabilities may occur before the potential emergence of a new wave of growth.     

The Relationship between Federal Deficits and Real Interest Rates

Real interest rates fluctuated a great deal since the 1970s. In the 1980s federal deficits accelerated and their impact on both nominal and real interest rates gained lots of attention. Based on monthly and quarterly data from January 1971 to December 1997 it is found that federal deficits had significant positive effect on the real interest rates: Personal income or consumption are found to have significant positive impact on the real interest rates, whereas expected inflation and money supply are found to have negative impact on the real interest rates. These findings are consistent with the conventional economic theory.     

从增长与通胀的多重组合看我国的滞胀风险

通过基本菲利普斯曲线及英变换，探讨增长与通胀的多重可能组合，分析了开放条件下菲利普斯曲线的变化以及“滞胀”组合的成因。在此基础上，重点回答中国是否面临“滞胀”风险，以及如何避免出现“滞胀”局面。     

A Sticky Information Phillips Curve for South Africa

Mankiw and Reis propose the Sticky Information Phillips Curve (SIPC) as an alternative to the standard New Keynesian Phillips Curve to address empirical shortcomings in the latter. A SIPC for South Africa is estimated, and we find estimates of information updating probability between 0.69 and 0.81, somewhat higher than suggested by methods using micro‐evidence. Because the estimation requires data on expectations of current period inflation and output gap conditional on sequences of earlier period information sets, we provide a detailed analysis of the impact on our estimates of alternative proxies available in South Africa.     

浅谈煤矿热交换站循环泵的选型

热交换站中的循环泵是整个采暖系统的核心设备,动力之源,重要性如同一个人的心脏,它的选型正确与否,直接关乎整个采暖系统的运转。本文对作者接触到的几个新建、改建的煤矿热交换站在循环泵选型上存在的误区进行分析,指出解决问题的对策。     

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.     

基于“学习曲线”效应的长期质量成本模型

企业质量管理中存在“学习曲线”效应。在传统质量成本模型中引入累积产量和学习率 ,形成了长期质量成本模型。该模型长期质量成本随累积产量的增加而下降 ,而不同时期的最适宜质量水平随累积产量的增加而提高并趋近于零缺陷水平。该模型的结果与六西格玛管理实践一致     

广义供给定律与房地产投机

在复杂的市场中,商品供给量的变化主要受制于行业利润率与平均利润率的比较,呈现随平均利润率上下波动的趋势。广义供给定律从平均利润率与行业利润率的角度研究了商品供给与价格的关系,揭示了商品供给量变化的规律以及房地产投机的根源。     

论如何同时降低通货膨胀率和失业率——菲利普斯曲线的微观经济基础及其移动

菲利普斯曲线有其微观经济基础。菲利普斯曲线描述的货币工资变化率与失业率之间的关系取决于失业工人随机寻找工作的经济决策、在岗工人与公司之间的博弈行为、工会势力与公司讨价还价力量的均衡、公司调整产品价格和工人工资的决定、劳动供给曲线的斜率等。以此为理论基础,通过对工作报价、最低工资预期水平、搜寻工作的效率、工会势力和公司势力、辞职率与临时解雇率、生产技术效率、劳动周转率、劳动市场分隔及其不平衡等因素进行政策性调节,可以使菲利普斯曲线整体性向左下方移动,从而同时降低通货膨胀率与失业率。     

经济发展、个人所得税调整与城镇居民收入差距

通过收集中国28个省、市、自治区2003—2012年的面板数据一方面验证库兹涅茨曲线在中国是否成立,另一方面,在库兹涅茨曲线基础之上验证2006年和2011年个人所得税调整对中国城镇居民收入差距的影响。实证研究结果表明,库兹涅茨曲线在中国显著存在,而且当人均实际GDP达到20 000元(2003年不变价格)左右时,中国城镇居民的收入差距随着人均GDP的进一步增加而逐渐下降,与跨国面板的实证结论一致。在该库兹涅茨曲线基础之上2006年个人所得税调整对城镇居民收入差距的影响不显著,而2011年的个人所得税调整则显著地降低了中国城镇居民的收入差距。