Disequilibrium models due to a “learning by doing” process

Sommario Si considerino fluttuazioni e crescita in un modello neo-keynesiano in tre diverse ipotesi macroeconomiche, che danno origine a diversi modelli matematici in tempo discreto, o mappe. In particolare si analizza un modello di crescita bidimensionale, rappresentato da un endomorfismo lineare a tratti. Separando il comportamento dinamico delle pendenze di rette che escono dall'origine, dalla dinamica dei punti su tali rette, si mostra che il comportamento dinamico del modello è governato dalla dinamica di un endomorfismo unidimensionale. Ciò semplifica lo studio dei valori di biforcazione che creano rette invarianti, su cui le traiettorie sono divergenti, e consente di determinare il bacino di attrazione di regioni assorbenti che contengono i cammini di crescita, regolari o caotici.

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Fluctuations and growth in a new-keynesian model are considered in three different macroeconomic assumptions, giving rise to different mathematical models in discrete time, or maps. In particular a two-dimensional growth model represented by a piecewise linear endomorphism is analysed. Separating the dynamics of the slopes of straight lines issuing from the origin, from those of the points on these lines, it is shown that the dynamics of the model are governed by the dynamics of a one-dimensional endomorphism. This simplifies the study of the bifurcation values which create invariant lines on which the trajectories are divergent, and enable us to determine the basin of attraction of the absorbing region which includes regular or chaotic growth paths.

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This paper relates to the activities of the M.U.R.S.T. Group Dinamiche Nonlineari ed Applicazioni alle Scienze Economiche e Sociali.     

“地王”收回·海南又“热”

“地王”收回节前,北京大龙地产“地王”项目被收回的消息引起了社会的广泛关注,这一事件的大致过程如下：2009年11月20日,北京市大龙房地产开发有限公司通过拍卖方式以50．5亿元竞得顺义区后沙峪镇天竺开发区22号住宅用地国有建设用地使用权,创下北京市公开出让土地以来的新高,成为北京土地市场总价和楼板价的“双料地王”。     

Introduction to “The Dual-Agency Problem of Labor Union Pension Fund Shareholder Activism”

Employee Responsibilities and Rights Journal -     

Some considerations about “Forecasting aggregates and disaggregates with common features”

Espasa and Mayo provide consistent forecasts for an aggregate economic indicator and its basic components as well as for useful sub-aggregates. To do so, they develop a procedure based on single-equation models that includes the restrictions arisen from the fact that some components share common features. The classification by common features provides a disaggregation map useful in several applications. We discuss their classification procedure and suggest some issues that should be taken into account when designing an algorithm to identify subsets of series that share one common trend.     

Some brief notes on the “unfinished business” of qualitative inquiry

The paper argues that there are a variety of implicit issues in qualitative inquiry that need to be addressed if the area is to develop in some normal science sense. This unfinished business is concerned with a deeper investigation of basic terms that are now simply taken for granted, such as theme and pattern. It also includes the need to develop rules which will assist in making and justifying how qualitative interpretations are made from the implicit processes of inference. Specific suggestions are made for accomplishing these issues.     

比尔·鲁阿内 眼“低”手“高”

作为红杉基金的创始人,比尔·鲁阿内总是谦逊地宣称自己只是一个“研究分析师”。但切莫让他的低调所迷惑,他绝对是个点石成金的高手,在名动天下的投资大师华伦·巴菲特的眼中,鲁阿内可是同辈人中最杰出的理财大师之一。30年前,当鲁阿内和合伙人理查德·坎尼夫创立红杉基金后,他的大部分客户都是由巴菲特介绍来的。尽管他知道声望会给自己带来     

Evaluation of the convergence between “self-reporters” and “proxies” in a disability questionnaire by means of behaviour coding method

Household surveys often require including proxy reporters to obtain information about other household members who cannot be interviewed. The participation of proxies can undermine survey data quality due to the fact that proxies must respond to questions thinking about other people. The objectives of the present study were to analyze the behaviour of proxy reporters and evaluate the convergence between the answers given by proxies and self-reporters by means of behaviour coding. This improves the evaluation of convergence, since only adequate (i.e., interpretable) answers given by both types of informant are taken into account. Responses to a disability questionnaire employed by an official statistical institute were analyzed. The questionnaire includes 11 questions about different limitations related to everyday activities. 16 self-reporter and 16 proxies formed 16 couples whose members lived together and supported a direct family relation. The results show a high percentage (52%) of convergence between both types of informant, although fluctuating across the questions and the couples. Proxies showed relatively more adequate behaviour during the interaction than self-reporters. From this we conclude that proxies can be considered at least as good informants as self-reporters from an interviewer-respondent interaction perspective. Future research should address the impact of proxy responses on survey validity.     

影像·空间“方程式”

室内设计和摄影有着纠缠不清的关系。 通过摄影的表现。人们既发现了室内设计的本质，而室内空间，也以摄影为镜鉴。其自我意识越来越强烈。     

印度“9·11”

印度金融中心孟买11月26日夜晚至27日发生多起爆炸袭击，伤亡400多人。 受全球金融危机影响，印度银行业面临资金大量外流，中央银行难以抵御货币卢比贬值压力，经济整体增长速度放缓。袭击者袭击印度金融中心外国人聚集的酒店等建筑，目的在于使市场动荡，吓跑投资者和游客，进一步打击投资者对印度经济的信心。     

由“3·15”想到“7·5”

我原来并不知道《消费权益保障法》颁布的日期。而且,说来惭愧,对于那部法律的内容也知之甚少。我国的法制建设尽管还处在起步阶段,但是施行的法律也已不少。对此孤陋寡闻或不求甚解,恐怕并不在少数。     

Introduction to “Breaking New Ground: Social Movement Theory and the Cincinnati Union Co-ops”

Employee Responsibilities and Rights Journal -     

新政“满月”·房产税渐近

新政“满月” 4月17日,国务院针对房地产市场出台的“新国十条”至今已过“满月”。一个多月以来,从中央各部委出台的调控政策,到各地方政府出台的实施细则,调控政策似乎一个比一个严厉。     

银行业的“本·拉登”

认真内向、不张扬、还很英俊,长得有点像汤姆·克鲁斯。这是盖维耶尔的父母和邻居对他的评价。他们怎么也无法想到这样一个老实的孩子却制造了法国金融界有史以来最大的一场地震。     

“金海岸·皇玛”——横空出世

从1999年始，番禺已连续稳坐广州市属区、市房地产交易面积的头把交椅多年，而且一直保持到现在4特别是随着广州市政府南拓蓝图的实施，带动市政配套建设到位、珠三角整合带来的发展商机以及番禺作为未来广州新中心城区的启动，都为番禺楼市注入了新的元素，有望继续保持领先的优势。