Economic Capacity Utilization and its Determinants: Theory and Evidence

This paper develops and estimates a model of economic capacity utilization and its determinants by allowing for the firm's full optimization behavior that considers endogenous output choice. The model consists of deriving the short-run output supply function and the capital demand function which generate optimal and capacity output. Optimal capacity utilization is determined as the ratio of optimal to capacity output and its determinants are identified. Evidence from U.S. manufacturing shows that capital expansion not accompanied by market growth and higher materials and capital prices has contributed to lower capacity utilization. Energy price increases have exerted a stimulating impact on capacity utilization. Conventional capacity utilization measures are found to be biased and fail to capture the influences of changes in economic conditions facing firms.     

国际油价冲击与中国的经济增长——基于非对称关系视角的分析

本文基于季度数据，引入非对称协整模型，考察国际油价与中国经济增长的动态关系，并鉴于油价波动对不发达经济体可能的冲击，还测度了油价的不确定性并探析其对经济增长的影响，结果表明：（1）从短期来看，国际油价变化是国内经济增长的单向Granger原因，“中国因素”对全球油价变化的影响尚不明显；（2）从长期来看，国际油价和经济增长具有非对称协整关系，油价上涨对经济的影响明显大于油价下跌所产生的效应；（3）国际石油市场存在正反馈交易行为，导致油价波动在油价上涨时表现更加明显。油价不确定性在短期内对经济增长存在负面影响，长期中则不会显著影响经济增长。以上结果意味着必须高度重视石油安全问题，加强油价波动预警与风险管理系统。     

Do the urban poor face higher food prices? Evidence from Vietnam

Whether there is a poverty penalty, in terms of food prices, is unsettled in the literature after more than four decades of study. Unit values from household surveys suggest that prices vary with income while outlet surveys typically find food prices varying with store type but not with neighborhood income. Most outlet surveys are from rich countries, with just one spatially limited study from a developing country. In this paper we use especially collected food price data from metropolitan areas of Vietnam to test whether the urban poor face higher food prices. Food prices in low-income neighborhoods are 1% lower, on average, than in other neighborhoods. Unit values give a different answer to the question of whether the poor face higher prices and are not suited to answer such a question.     

Non-parametric production analysis in non-competitive environments

We extend the non-parametric methodology for empirical production analysis to deal with endogenous prices. As price endogeneity is often complemented by price uncertainty, we consider both the case of certain prices and the case of uncertain prices. The extensions are fully compatible with existing tools for eliciting and representing technology and price information, and preserves the tractable mathematical programming structure of the original methodology. An empirical application to the Dutch electricity distribution sector illustrates our extension.     

Market integration and price transmission in consumer markets of developing countries

World prices for agricultural commodities surged in 2006–08, and then again in 2011–12. In many developing countries, consumer prices for staple foods, such as bread and rice, mirrored these movements. This paper examines whether prices in urban consumer markets within developing countries are co-integrated with prices in world agricultural commodity markets. Using a single equation error correction model, we examine the response of consumer prices for wheat, rice, maize, and sorghum to changes in world market prices and exchange rates in urban centers of the developing world. Analyzing over 60 country/commodity pairings, we find that developing countries’ consumer markets are co-integrated with world markets. Yet, we also find that the transmission of changes in both world prices and real exchange rates to domestic consumer prices is not high, and that the movement of domestic consumer prices to new equilibrium with world prices after a shock to the latter is relatively slow.     

Production planning: An improved hybrid approach

This paper proposes an extended linear programming model for the hybrid approach proposed by Byrne and Bakir (International Journal of Production Economics 59 (1999) 305) and Kim and Kim (International Journal of Production Economics 73 (2001) 165). In this new model the workload of jobs is sub-divided to introduce the unit load concept of JIT. While an optimum plan is sought, due to this unit load concept, the model takes account of the requirement of small lot sizes which is one factor of the JIT approach. The effective loading ratio (ratio of the output quantity to the input quantity) is modified by omitting the slack time for each job. This helps to ensure that correct quantity of product is produced in each period, thus minimising any excess inventory or backlogging. Omission of slack time will also improve equipment utilisation and throughput. A flexible capacity constraint is also introduced which takes into account the availability of resources based on their previous histories.The incorporation of the unit load concept and modification of resource requirements and constraints in the proposed LP formulation are expected to help to improve the planning model by reducing the level of WIP and total flow time.     

Collusion Under Imperfect Monitoring with Asymmetric Firms

We explore the effects of asymmetries in capacity constraints on collusion where market demand is uncertain and where firms’ sales and prices are private information. We show that all firms can infer when at least one firm's sales are below some firm‐specific ‘trigger level.’ When firms use this public information to monitor the collusive agreement, price wars may occur on the equilibrium path. Symmetry facilitates collusion but, if price wars are sufficiently long, then the optimal collusive prices of symmetric capacity distributions are lower on average than the competitive prices of asymmetric capacity distributions. We draw conclusions for merger policy.     

Group purchasing, nonlinear tariffs, and oligopoly

Loyalty discounts are nonlinear tariffs that condition rebates or marginal prices on meeting aggregate purchase or market share targets. These discounts are widespread, and are often the impetus for consumers to form buying groups, or group purchase organizations (GPOs). This paper models the competitive effects of the introduction of a GPO into a market within which the preferences of the GPO's members are horizontally differentiated. While nonlinear tariffs are an effective way for a monopolist to extract consumer surplus, when two suppliers compete using such schedules, the results are far more competitive in comparison to simple Bertrand–Nash competition with linear tariffs. This result holds when the product of each of the suppliers is attractive to a substantial portion of consumers. In our model, the nonlinear schedule puts all customers “in play” to a degree that contrasts sharply with the competition at the margin characteristic of constant per unit prices. Moreover, competing in nonlinear tariffs removes allocative inefficiency that can result from single price competition.     

产品结构优化中应注意的几个问题

在运用线性规划方法优化企业的产品结构时，应当在目标函数中引入产品价格和各种资源的价格等信息，用单位产品的毛利作为目标函数中决策变量的系数。并应根据使硬约束成为紧约束的原则，不断调整软约束的资源可用量，尽可能使所有的约束条件都达到紧约束的程度，才能保证得到最优方案。     

Economic factors affecting the increase in obesity in the United States: Differential response to price

A sharp increase in obesity during the last 15 years in the United States became one of the nation’s main public health problems. The theory of rational addiction seems to explain human behavior in food consumption leading to obesity reasonably well. The interesting thing about our results is that the tax policy, normally used to correct various distortions, is to serve in this case as the preventive policy: additional taxes on future prices of the addictive (sweet) foods contribute to lower sugar consumption and BMI at present time. On the other hand, increasing education level is usually considered a preventive type of policy. In this case, it leads to lowering the levels of the BMI in already overweight and obese population.     

Testing for Cointegration between House Prices and Economic Fundamentals

Economic theory predicts three possibilities for the cointegration relationship between house prices and economic fundamentals: linear cointegration, nonlinear cointegration and no cointegration. In contrast, the empirical literature has only examined linear cointegration. This article argues that ignoring nonlinear cointegration may lead to misleading conclusions that no cointegration exists between house prices and the fundamentals. To illustrate this point, I test for cointegration for ten U.S. cities and find that only one city shows evidence of linear cointegration. Further analysis using the two‐step testing procedure yields evidence of nonlinear cointegration for six other cities. Still, there are three cities left out without evidence of nonlinear cointegration. Further studies are needed to test for other forms of nonlinear cointegration before a conclusion of no cointegration can be reached for the remaining three cities.     

Local Energy Markets*

In current power markets, the bulk of electricity is sold wholesale and transported to consumers via long-distance transmission lines. Recently, decentralized local energy markets have evolved, often as isolated networks based on solar generation. We analyze strategic pricing, investment, and welfare in local energy markets. We show that local energy markets yield competitive equilibrium prices and provide efficient investment incentives. Yet, we find that strategic behavior leads to allocative inefficiency. We propose a clearing mechanism that induces truth-telling behavior and restores first-best welfare.     

Innovations,Prices and Employment: A Theoretical Model and an Empirical Application for West German Manufacturing Firms

In this paper a theoretical model of the impact of product and process innovations on output, capacity utilization, employment and prices is developed. The model is estimated with a unique set of micro-data from West German manufacturing firms. The empirical results reveal that innovative firms are more successful. They show a higher utilization and more output and employment growth than non-innovative firms. Innovations also change market behaviour. In sectors with a large share of product innovators, firms more often change employment and less often change prices, i.e. product innovations reduce price competition.     

Commodity prices, trade, and poverty in Uruguay

The 2006-2008 food price spike raised concerns about the impact of high commodity prices on poverty in developing countries. This paper addresses these concerns in relation to Uruguay, a small country that exports agricultural commodities and imports fuels. Applying a general equilibrium model, we find that, as a whole, an increase in commodity prices has a positive effect on the economy of Uruguay. Benefits obtained through a growth in export activities are partially outweighed by an increase in crude oil prices. In this context, extreme poverty increases. As in other countries, the increase in food prices affects the already poor population, who become even poorer. This fact highlights the need for policies that mitigate the negative effects of price shocks.     

Defining inventory control points in multiproduct stochastic pull systems

Multistage pull production systems have been widely implemented in recent years and constitute a significant aspect of lean manufacturing. One of the important considerations in such systems is identifying the control points, i.e. where in the multistage sequence to locate the output buffers. Allowable container/batch sizes, optimal inventory levels, and ability of systems to automatically adjust to stochastic demand depend on the location of these control points yet the issue of optimal location has not been widely addressed. This paper considers a multiproduct pull setting where part types compete with each other for common production resources. In this environment it is important to consider factors such as lead time variability and to include the corresponding queuing aspects into the model. Each workstation is modeled as a GI/G/1 queue. Waiting times spent by parts at workstations are approximated using a decomposition/recomposition algorithm. Necessary and sufficient conditions are provided for the optimality of a single control point. Conditions under which multiple control points are optimal are investigated along with the impact of product mix and utilization parameters on the number of control points. Analytical model results are validated by simulation.     

A multi-objective robust optimization model for multi-product multi-site aggregate production planning in a supply chain under uncertainty

Manufacturers need to satisfy consumer demands in order to compete in the real world. This requires the efficient operation of a supply chain planning. In this research we consider a supply chain including multiple suppliers, multiple manufacturers and multiple customers, addressing a multi-site, multi-period, multi-product aggregate production planning (APP) problem under uncertainty. First a new robust multi-objective mixed integer nonlinear programming model is proposed to deal with APP considering two conflicting objectives simultaneously, as well as the uncertain nature of the supply chain. Cost parameters of the supply chain and demand fluctuations are subject to uncertainty. Then the problem transformed into a multi-objective linear one. The first objective function aims to minimize total losses of supply chain including production cost, hiring, firing and training cost, raw material and end product inventory holding cost, transportation and shortage cost. The second objective function considers customer satisfaction through minimizing sum of the maximum amount of shortages among the customers’ zones in all periods. Working levels, workers productivity, overtime, subcontracting, storage capacity and lead time are also considered. Finally, the proposed model is solved as a single-objective mixed integer programming model applying the LP-metrics method. The practicability of the proposed model is demonstrated through its application in solving an APP problem in an industrial case study. The results indicate that the proposed model can provide a promising approach to fulfill an efficient production planning in a supply chain.     

Pricing in revenue management for multiple firms competing for customers

We consider the pricing strategies of multiple firms providing the same service in competition for a common pool of customers in a revenue management context. The firms have finite capacity and the demand at each firm depends on the selling prices charged by all firms, each of which satisfies demand up to a given capacity limit. We use game theory to analyze the systems when firms face either a deterministic demand or a general stochastic demand. The existence and uniqueness conditions of a Nash equilibrium are derived, and we calculate the explicit Nash equilibrium point when the demand at each firm is a linear function of price. We also conduct sensitivity analysis of the equilibrium prices with respect to cost and capacity parameters.     

Examining the link between food prices and food insecurity: A multi-level analysis of maize price and birthweight in Kenya

In developing countries where many poor people rely on rainfed, locally produced food for the majority of their caloric intake, shifts in climate and weather patterns can dramatically reduce agricultural productivity. The reduction in agricultural productivity reduces overall food availability and ultimately impacts food accessibility, putting millions of people at risk for malnutrition. In this project we focus on Kenya where roughly a third of households are food insecure. We examine the relationship of the price of maize and low birth weight to help quantify the impact of local food prices on one outcome of household food insecurity. Using spatially referenced data from recent Kenyan Demographic and Health Survey datasets, price data, livelihood information, and a remotely sensed-based measure of local growing season productivity, we develop a dataset linking pregnancies occurring from 2001 to 2008 to the spatially and temporally relevant maize price data. We construct several regression models to examine the impact of local maize prices and remotely sensed based estimates of crop production on infant birth weight – specifically low birth weight. The results of the models highlight the importance of including community crop production to evaluate maize price impacts on low birth weight outcomes. Also, because of the positive correlation between pre-pregnancy maize prices and birth weight, the results suggest that some households may benefit from high prices or that high prices may impact the number of conceptions. More generally, our work demonstrates that multilevel models that account for community-level variation are important for disentangling these complex relationships and can contribute to the discussion of how to design more effective food policies.     

Tight Average Revenue Regulation Can Be Worse Than No Regulation

Price regulation of a multi-market monopolist, with the cap based on average revenue, can cause welfare to be below the unregulated level. In a model with linear demands and constant but unequal marginal costs, a sufficient condition for this welfare effect is that the cap equals the average revenue that would be earned with marginal cost pricing. Relaxation of the price cap can lower all prices. Welfare with uniform pricing at the level of the price cap can be above or below the average revenue welfare level.     

利用Excel软件优化氢气使用成本

分析了齐鲁石化公司范围内的适宜作制氢原料的气体资源，并运用线性规划法对制氢原料和公司氢气使用进行优化，建立了齐鲁石化公司氢气使用成本的线性规划模型，并提出了氢气的优化原则。