Estimating demand with distance functions: Parameterization in the primal and dual

Our purpose is to investigate the ability of different parametric forms to ‘correctly’ estimate consumer demands based on distance functions using Monte Carlo methods. Our approach combines economic theory, econometrics and quadratic approximation. We begin by deriving parameterizations for transformed quadratic functions which are linear in parameters and characterized by either homogeneity or which satisfy the translation property. Homogeneity is typical of Shephard distance functions and expenditure functions, whereas translation is characteristic of benefit/shortage or directional distance functions. The functional forms which satisfy these conditions and include both first- and second-order terms are the translog and quadratic forms, respectively. We then derive a primal characterization which is homogeneous and parameterized as translog and a dual model which satisfies the translation property and is specified as quadratic. We assess functional form performance by focusing on empirical violations of the regularity conditions. Our analysis corroborates results from earlier Monte Carlo studies on the production side suggesting that the quadratic form more closely approximates the ‘true’ technology or in our context consumer preferences than the translog.     

双液位计量分离器计算原油产量与含水率及理论

克拉玛依油田稠油和稀油的生产过程中，对油井产出液的含水率测定，经历过化验、含水分析仪两个阶段。含水分析仪在测定稠油含水率时，黏液粘在含水分析仪的探头上时而测得含水率100％，时而含水为零，含水分析仪在稠油的生产过程中有很大的局限性。利用油水密度差的特性，通过两个液位计的位差计算出井流物的含水率。在油井的生产中期以前准确度高，操作方便，成本低。     

Biases in demand analysis due to variation in retail distribution

Aggregate demand models typically assume that consumers choose between all available products. Since consumers may be unwilling to search across every store in a given market for a particular item, this assumption is problematic when product assortments vary across stores. Using supermarket scanner data for five product categories we demonstrate that approximately one third of products have limited retail distribution, which account for one fourth of dollar sales. Monte Carlo analysis demonstrates that the level of limited product availability observed in the data can significantly bias the results of aggregate demand models that incorrectly assume all consumers in a given market face the same choice set.     

Credit Conditions in Pakistan: Supply Constraints or Demand Deficiencies?

This paper attempts to pin down the key drivers of demand for and supply of real private sector credit in Pakistan. I use both the equilibrium and disequilibrium econometric frameworks, specifically tackling the issue of lack of consistency and/or efficiency of joint estimators in the former via the three‐stage least squares technique. On the demand side, I find that higher economic activity provides stimulus to credit whereas inflation dampens it. The stock market seems to play a dual role: as a source of alternative financing, a bullish market negatively impacts credit while, as an indicator of economic expectations, it provides a positive impetus. On the supply side, banks' lending capacity is found to be the major driver of credit while government borrowing has a crowding‐out effect. Pakistan currently faces supply constraints, which might put an additional check on capacity utilization by firms, thus damaging growth prospects. The results have important policy implications.     

When trade hurts: Consumption indivisibilities and labor market distortions

We present a simple model where complementarities between wages and demand due to factor market distortions can make a transition economy worse off from trade. Prior to trade, a virtuous circle prevails: high wages in industry support a high demand for indivisible industrial goods, which in turn supports high wages. However, factor market distortions in the transition economy create a comparative disadvantage in industry. Opening up to trade results in the import of indivisibles and a fall in manufacturing wages, breaking this virtuous circle. Consequently, trade liberalization without structural reform can have serious adverse effects in a transition economy.     

我国石油对外贸易流量分析与对策研究

石油是关系国家经济安全的重要战略物资,本文通过对我国石油进出口贸易一些流量指标的分析,发现:(1)石油净进口量过大,进口依存度偏高,并有逐年递增的趋势;(2)原油进口的地区集中度偏高,不利于石油资源供应稳定;(3)国际油价持续高企,对国内经济稳定造成威胁。并据此提出了相关政策建议。     

不同萃取试剂检测羽绒残脂率的差异性分析

选用乙醚、二氯甲烷和石油醚作为羽绒残脂率的萃取试剂,对3种试剂检测结果进行了比对分析。结果显示：二氯甲烷检测结果高于乙醚的检测结果,而石油醚的检测结果低于乙醚的检测结果。从统计学角度分析得出这两种试剂的检测结果与乙醚的检测结果都存在显著性差异,二氯甲烷和石油醚无法直接作为乙醚萃取的替代性试剂。     

Market shares analysis: The Case of French Tourism Demand

This paper examines the magnitudes and determinants of changes in destinations’ shares of a major tourist origin market. The Almost Ideal Demand System model is used to quantify the responsiveness of French tourism demand in Italy, Spain, and the United Kingdom to changes in relative prices, exchange rates, tourists’ expenditure budget, and external events. The results indicate that effective price competitiveness is a key variable driving changes in market shares. Policymakers who wish to maintain their shares of the French market should pay particular attention to tourism pricing policies, as well as to improving the tourism offer.     

An Empirical Investigation of Trade Credit Demand

This paper investigates the motivations for a firm's demand for trade credit. Demand for credit is modelled as a function of transaction costs motivations, financing motivations, operational considerations, seller compliance issues and supplier marketing, whilst controlling for the firm's business environment and for firm characteristics such as size and industry. This paper builds on previous studies by considering a wider range of factors that can affect trade credit demand holistically on a single sample. It appears that the use of trade credit is widespread, and that it is generally perceived as an important short term financing option, although the availability of trade credit is not a major influence on supplier choice. The level of a firm's trade credit demand is found to be significantly influenced by transaction costs, financing, operational issues, marketing activities by suppliers, the firm's investment in trade debtors and firm size.     

我国第三产业的供需矛盾及政策取向

经过改革开放20多年的发展,我国第三产业从原来明显的需求大于供给转变为弱的需求大于供给的矛盾,但结构性供需不平衡的问题仍然较为突出.为了刺激服务需求上升,政策取向应该是设法增加城乡居民收入,进一步降低服务产品价格,加速城市化进程,进一步提高城市人口密度,调整工作和休假时间,促进生产社会化和专业化程度的提高,支持和鼓励服务产品出口.为了增加服务供给,政策取向要进一步在资金上向第三产业倾斜,提高第三产业从业人员素质,充分发挥技术、制度等综合要素对第三产业发展的促进作用,有选择、有重点地鼓励对国外服务产品的消费.