随机需求环境下联产品系统价格与产量决策研究

基于固定比例生产技术和多产品随机需求的情形,研究了联产品制造商的两阶段产量和价格联合优化模型。通过反向倒推的优化求解,得到了联产品制造商的最优产量和价格决策以及变化规律。同时研究了需求服从均匀分布时,需求波动对均衡的影响。研究结果表明,在订货成本较低和一种产品的需求波动性较大时,当另外一种产品的波动增大,则该产品的最优订货量增大,同时价格下降。借助数值仿真,分析了价格敏感度和产出比例对最优决策和利润的影响。结果表明,在给定一种产品的价格敏感度时,另外一种的价格敏感度越大,那么该产品的价格就越低,制造商的订货量就下降。当一种产品的产出比例固定时,另一种产品的产出比例上升时,则该产品的价格下降,制造商的订货量下降,总利润上升。     

重庆市都市区人中就业现状及变化趋势

都市区作为重庆经济的核心区域,随着经济的快速发展以及城市化进程的加快,正对人口产生巨大的聚集效应,而人口就业将成为一个十分突出的问题。因此,准确把握劳动力供求变动趋势十分重要。为此通过模型运算,对2000-2020年的都市区劳动年龄人口和劳动力的供求变动趋势进行了预测分析。     

盛世丹青——刘宇一和他的绘画创作

面对宇一的历年画作 ,可以排成一个大型的方阵 ,其中贯穿着一条线 ,就是对主题性绘画的追求和色调的清新明丽。诗人艾青说 :“我生活 ,故我歌唱。”那么 ,宇一呢 ,当然是奋挥手中的巨笔 ,再创新的辉煌。这是时代的要求 ,是中国美术史的一个新的篇章     

Olive Oil Consumption in Greece: A Microeconometric Analysis

In this paper, the factors affecting at-home demand for three types of oils and fats in Greece, with emphasis on olive oil, are investigated using the linear approximation of the Almost Ideal Demand System and family budget survey data. To overcome the econometric problem created with the existence of zero expenditure, a generalization of the two-stage Heckman procedure is employed. In order to investigate the role of self-consumption, two different samples were used. The first includes all households; the second excludes those that acquire olive oil only from own production. According to the results, there are important differences in the first stage of the decision process between the two samples. Unlike the first stage, the second stage of the decision process found no important differences between the results for the two samples.     

中国近年来消费需求增长乏力的原因探析

消费需求增长乏力是近年来我国宏观经济面临的突出问题,这是居民消费能力、消费动力和消费环境三方面因素共同作用的结果。首先,居民收入增加与GDP增长不同步导致居民消费能力有限,而收入差距不断拉大则引起消费能力分配失衡;其次,未来收入和支出的预期不稳定、消费信贷制度滞后等在很大程度上降低了居民消费动力;最后,相关配套体制和设施不健全、与市场经济不协调的消费习惯等也都影响了消费需求的增加。     

Bias Correction in the Dynamic Panel Data Model with a Nonscalar Disturbance Covariance Matrix

Approximation formulae are developed for the bias of ordinary and generalized Least Squares Dummy Variable (LSDV) estimators in dynamic panel data models. Results from Kiviet [Kiviet, J. F. (1995), on bias, inconsistency, and efficiency of various estimators in dynamic panel data models, J. Econometrics68:53-78; Kiviet, J. F. (1999), Expectations of expansions for estimators in a dynamic panel data model: some results for weakly exogenous regressors, In: Hsiao, C., Lahiri, K., Lee, L-F., Pesaran, M. H., eds., Analysis of Panels and Limited Dependent Variables, Cambridge: Cambridge University Press, pp. 199-225] are extended to higher-order dynamic panel data models with general covariance structure. The focus is on estimation of both short- and long-run coefficients. The results show that proper modelling of the disturbance covariance structure is indispensable. The bias approximations are used to construct bias corrected estimators which are then applied to quarterly data from 14 European Union countries. Money demand functions for M1, M2 and M3 are estimated for the EU area as a whole for the period 1991: I-1995: IV. Significant spillovers between countries are found reflecting the dependence of domestic money demand on foreign developments. The empirical results show that in general plausible long-run effects are obtained by the bias corrected estimators. Moreover, finite sample bias, although of moderate magnitude, is present underlining the importance of more refined estimation techniques. Also the efficiency gains by exploiting the heteroscedasticity and cross-correlation patterns between countries are sometimes considerable.     

浅析英国工业革命的市场条件

国内外市场的存在及市场需求的不断增长的压力是英国工业生产发展的主要动因。英国可资利用的市场规模远较欧洲其它国家的市场大,这大大便利了英国工业品的生产与销售。英国市场的性质也有助于工业再生产的进行。     

Firm-level training in local economic systems: Complementarities in production and firm innovation strategies

The paper presents a conceptual review over the main aspects concerning the role of human capital investments and training activities within production processes, followed by empirical evidence on two local economic systems in Northern Italy, based on recent survey data. Theoretical and empirical considerations are brought together in order to provide new insights on the role of training and the factors associated to training activities at firm level.The potential driving factors of training here analysed compounds structural characteristics, labour demand dynamics, human resource management practices, workforce features, and firm performances. We observe that training activities emerge positively associated with high-performance practices, innovative labour demand features, workforce skill level, firm size, and are affected by labour flexibility in various directions. Empirical evidence confirms most previous results but also adds further important insights. The analysis suggests that a widening gap, between few innovatively evolving and many stagnant firms, could characterise the future dynamics of the Region. The high relevance of structural variables, labour demand factors and HRM/innovation practices shows that regional industrial policies and labour policies should be jointly implemented for increasing potential firm productivity. This is a key concern for the current debate on local systems economic development in the European and Italian environment.     

论知识与知识性劳动

本文针对知识经济来临时代一些人对价值源泉的模糊认识,结合新的实际,在马克思主义经济学理论框架内对知识、知识性劳动进行了分析,在新的经济条件下发展了商品二因素理论和劳动二重性理论.在知识经济时代,人类劳动的主体形式从体力劳动转向智力劳动,知识成为当代经济发展的重要因素,但价值的源泉仍旧是人类劳动.本文通过区分知识和知识性劳动,澄清了模糊认识,阐明是知识性劳动创造了价值,而不是知识创造了价值.知识性劳动就是人们不断探索的劳动,从而知识经济的本质是创新,只有坚持劳动价值论,我们才能在知识经济社会中建立一个以人为本的、不断创新的经济运行机制.     

The econometrics of female labor supply and children

This is a survey of applied econometric research on the effects of children on female labor supply. Reasons for interest in the topic, and a basic model and terminology, are reviewed. Concerns are raised about the possible endogeneity of child status variables, and about the instrumental variables approach for dealing with this problem. Alternative ways of conceptualizing and estimating child status effects are considered, together with selected empirical evidence. Relevant developments from the household demand literature are summarized. Basic issues of model choice are also discussed.