New batch construction heuristics to optimise the performance of order picking systems

Two new batch construction heuristics called K-means Batching (KMB) and Self-organisation Map Batching (SOMB) are developed and verified by simulation experiments. Both KMB and SOMB have a preferment of superior performance in total travel distance and average picking vehicle utility, and even a conspicuous improvement in total CPU running time. Besides, this paper investigates the overall performance of order picking systems integrating storage assignment, order batching and picker routing to find the optimal policy combinations under different order types. The sensitivity analysis is performed to distinguish the relative importance of the various strategies to enhance the performance of operations management.     

Optimizing the storage assignment in a warehouse served by milkrun logistics

This paper addresses the problem of storage assignment in a warehouse characterized by multi-command picking and served by milkrun logistics. In such a logistic system, vehicles circulate between the warehouse and the production facilities of the plant according to a pre-defined schedule, often with multiple cycles (routes) serving different departments. We assume that a request probability can be assigned to each item and each cycle, which leads to a special case of the correlated storage assignment problem. A MIP model is proposed for finding a class-based storage policy that minimizes the order cycle time, the average picking effort, or a linear combination of these two criteria. Computational experiments show that our approach can achieve an up to 36–38% improvement in either criterion compared to the classical COI-based strategy.     

An economic analysis of deferred examination system: Evidence from a policy reform in Japan

We investigate how a deferred patent examination system promotes ex-ante screening of patent applications, which reduces both the number of granted patents and the use of economic resources for examinations, without reducing the return from R&D. Based on a real option theory, we develop a model of examination request behaviors. Exploiting the responses of Japanese firms to recent policy reform, we find that the shortening of the allowable period for an examination request significantly increases both eventual and early requests, controlling for the blocking use of a pending patent application. This effect is stronger in technology areas with higher uncertainty. These results support the importance of uncertainty for an applicant and of ex-ante screening.     

An industrial analysis market information system

The United States maritime industry share of world cargo movement has declined steadily for the last decade. The authors maintain that this situation is partially due to the industry's lack of a marketing orientation. Successful marketing hinges upon an effective market information system. This paper presents such a system for the U.S. maritime industry and discusses various information sources as a foundation for this system.     

电力系统灾害对社会经济发展影响的定性定量分析

随着社会经济的发展,随着人类对电力的需求和依赖正变得越来越强烈,电力系统灾害问题也日益突出。基于此,本文从全社会的角度出发、分析了电力系统灾害对社会经济发展的影响,特别地从经济学角度,定量地分析了电力系统灾害对经济增长率的影响。     

Analytical analysis of a generic assembly system

The assembly of components is a key element in manufacturing facilities. Nevertheless, literature analyzing the dynamic behavior remains scarce. The paper narrows this gap by studying a generic first-come first-serve assembly system, consisting of two generally distributed component input streams. The field of probability theory serves as a means to derive good approximations for the waiting time of the components to form a kit and the inter-arrival time of the kits at the assembly station. Apart from providing insight in generally accepted managerial principles, this analysis also constitutes a required step in obtaining the performance of an open queuing network including assemblies.     

An analysis of the inventory behavior in a q-theoretic framework

This paper develops a generalized q-model in which a monopolist with perfect foresight holds inventories. This model permits an analysis of the dynamics of inventories in the presence of various types of deterministic demand and supply shocks. The results suggest that if only positive inventories are allowed, inventories are more successful in smoothing expected upward than downward variations in demand. If unfilled orders are permitted, then production smoothing accompanies any type of demand shock, but inventories are generally negative. The estimation of the linear quadratic model on data generated using the two versions of the generalized q-model shows that incentives to smooth production appear only when the firm is allowed to have negative inventories.     

Foreign direct investments by Korean firms: An analysis with FDI theories

This paper analyzes data on foreign direct investment (FDI) by Korean firms in the light of eight propositions drawn from the literature on FDI which includes both the theoretical and empirical findings of studies on FDI by Third World Multinational Corporations (MNCs). The data concern FDI in manufacturing, natural resources, construction, banking and other industries. The propositions examined include the nature of ownership advantages, the trade-orientation of FDI, and motivations behind the overseas expansion of Korean banks. In addition, the geographical distribution and ownership patterns which arise as a result of these variables are also examined. The findings are generally consistent with many of those in previous theoretical and empirical studies and suggest that an eclectic approach, incorporating many explanatory variables, could adequately explain the patterns in Korean outward FDI.The authors are from School of Business Administration, The University of Michigan and School of Business Administration, Georgetown University, respectively. They gratefully acknowledge the valuable suggestions by Professors Sang Kee Min of Seoul National University and Adrian E. Tschoegl of The University of Michigan. They also acknowledge the cooperation of officers in the Bank of Korea, Korea.     

Bids for the UMTS system: An empirical evaluation of the Italian case

The aim of this paper is to analyze the licensing of the telecommunication spectrum as a public good and the search for equilibrium prices through bilateral bargaining and multilateral bidding. It develops a general model of price setting under dynamic uncertainty and applies it to the Italian auction for Universal Mobile Telecommunications System (UMTS). The empirical application shows that the model can be used both to determine the base price as well as other desirable characteristics to organize an auction and to better understand, after the auction is closed, what really happened in terms of the critical factors involved. After recalling some basic concepts on spectrum rights and reviewing the general experience with UMTS auctions in Europe, the formal model and its application are presented. The results confirm certain views on the Italian auction, which are widely shared but were never tested before, namely that: (i) given the initial price, the number of licenses offered for the bidding should have been fewer, or alternatively, (ii) given the number of licenses, the base price should have been higher and (iii) the main bidder underpaid for the license. The model also allows us to quantify the bidders’ reservation price and the State and the bidders’ implicit bargaining powers.     

Estimating risk-return relationships: An analysis of measures

We show that the risk-return paradox can be partly explained by the choice of accounting risk and return measures. Returns computed with equity or assets from End-of-Period (EOP) annual reports produce negative risk-return associations, while measures calculated using Beginning-of-Period (BOP) equity or assets yield more positive relationships. The likelihood of reporting negative relationships using EOP methods is accentuated by dividing samples at median returns. Below-median firms suffer losses and may appear to have lower and more variable returns than above-median firms, simply because of EOP methods. Our results show that mean and variance measures are unstable and risk-return relationships vary inversely the number of firms reporting mean losses.     

Entry into auctions: An experimental analysis

This paper investigates entry decisions into first and second-price auctions using an experimental design to extract information on willingness-to-pay to enter (WTE). We find that subjects tend to overpay to enter both auction formats. In particular, if the subjects believe they will be bidding against bidders following the risk-neutral Nash strategy, their WTE is greater than the optimal risk-neutral amount 97% of the time for first-price auctions (FPA) and 90% for second-price auctions (SPA). If they believe that they are bidding against subjects who bid as do the other subjects, they submit a WTE that is too high 92% of the time for FPA and 69% of the time for SPA. We also find, in line with previous studies, significant overbidding in both the FPA and SPA. We then investigate whether introducing risk aversion (RA) or “joy of winning” (JOY) can explain the joint observation of over-entry and overbidding. In particular, using bid data alone, we structurally estimate three models, one allowing RA only, one allowing for JOY only and one allowing for both RA and JOY. While a model with JOY alone overestimates WTE, we find that RA alone can explain 38% of WTE but a model with both RA and JOY (where RA is estimated using FPA bids, and JOY is estimated using SPA bids) can explain 65% of WTE. Moreover, JOY appears to explain nearly all of the male WTE but only 44% of the female WTE.     

Worst-case analysis of the full load policy in the single link problem

The full load policy is a popular heuristic solution of the problem of shipping several products from a common origin to a common destination with the aim of minimizing the sum of inventory cost and transportation cost over an infinite time horizon. We show that, although this policy gives in the worst case an infinitely large error with respect to the optimum, there exists a class of instances in which it is better than the best single frequency policy. Moreover, we show that there exists an instance in which this policy allows to reduce significantly the total cost with respect to the best possible frequency-based policy with any number of transportation frequencies.     

An empirical analysis of organizational strategies by entrepreneurial high-technology firms

Many start-up, high-technology firms commercialize an emerging technology through cooperative arrangements. This paper empirically investigates the determinants of entrepreneurial high-technology firms to form cooperative relationships. The statistical results on data drawn from the commercialization of the new biotechnology show that the propensity to cooperate is positively correlated with the distance of firms' competitive position in relation to their rivals. The follower is more likely to seek cooperative relationships than the leader in commercializing new products. However, the competitive pressure impacts firms in different ways, depending on their internal capabilities to commercialize a new product. We found that firm size is negatively correlated with the use of cooperative arrangements. The study also found that the organizational mode of cooperative arrangements is predominantly selected by the high-tech. start-up firm in commercializing their new products in foreign markets.     

Towards a better understanding of partnership attributes: An exploratory analysis of relationship type classification

In recent years the creation of partnerships has been espoused by academics and practitioners but despite extensive writing in the area of characterizing partnerships the nature and attributes of partnerships are still only poorly understood. This is due to a lack of empirical testing of the factors that distinguish partnerships from other relational forms and a limited research focus on characteristics that distinguish between polar relationship types. Using a framework developed from the political economy literature this exploratory study draws on an empirical base of 155 supplier questionnaires and uses multiple discriminant analysis to identify attributes of buyer-supplier relationships that most effectively discriminate between relationships classified by suppliers as having limited coordination, being highly coordinated or best described as a partnership. The results indicate that 8 of the 10 attributes of buyer-supplier relationships included in the framework differ significantly across relationship type.     

Consumer preferences before and after a food safety scare: An experimental analysis of the 2010 egg recall

In August 2010, more than half a billion eggs were recalled in the U.S. because of a Salmonella outbreak. This study examines the effect of the recall with a unique pair of auction experiments investigating willingness to pay (WTP) for conventional and organic eggs, one conducted shortly before and one right after the recall with the same participants. In addition to the before and after bids, participants bid again after a negative information or balanced information treatment about the event. Accompanying surveys showed consumers had a high level of awareness of the recall but less knowledge of specific details, and viewed information on egg farm conditions as very important in their WTP. While there were no significant before and after differences, WTP for organic eggs significantly increased in the negative information treatment, and balanced information had a positive effect on consumer WTP for conventional eggs.     

Unleashing the potential of online learning in Spain: An econometric analysis

Online learning and training continue gaining momentum worldwide resulting in the reduction of the traditional form of face-to-face education with its temporal and spatial limitations. Online education improves access to education and training, as witnessed during the Covid-19 pandemic. This article focuses on online education adoption in Spain. A representative survey on ICT use in households conducted annually by the Spanish National Institute of Statistics is used to construct a panel database for the years 2008–2020. The first objective is to provide an econometric model for adopting online education using this panel data. Next is to measure the effects of relevant observable individual socioeconomic variables on adoption. A Heckman selection model allows for estimating the impact of gender, age, education, digital skills, habitat, and income. The article also measures the effects of Covid-19 in 2020 on different population groups. The drivers and impediments have the expected signs and plausible sizes. The paper concludes with policy recommendations and suggestions for further research.     

An improved maize marketing system for African countries: the case of Zimbabwe

This article proposes a system for Zimbabwe which retains government control of national stocks and enables the parastatal marketing system to stabilize prices, at the same time ensuring a more rational delivery system in rural areas with prices reflecting storage and transport costs. The local population is encouraged to fulfill local needs, thus avoiding the expense of directing all marketing and processing through the urban areas. A more localized system will also have greater multiplier effects. Zimbabwe's maize marketing system is used to show how this system could be modified with benefits to rural consumers, producers and government. Data suggest there is little market exploitation: price differentials between markts reflect transport costs, returns on storage are reasonable, and voluntary procurement operations are usually able to stabilize prices. Zoning, movement restrictions and compulsory procurement have been shown to destabilize food markets; prices between markets are higher in periods of strict control than when marketing is relatively free. Controlled marketing answers a real political and economic need in Zimbabwe. Existing public food marketing agencies are not inherently inefficient. While stabilizing maize supply, there are important advantages in announcing preplanting prices, but any trade in maize only takes place after price setting. It is unlikely that there would be both imports and exports in any 1 year, except when previous contracts are being fulfilled. 2 policy options are available to cover anticipated periods of insufficient national maize production: the maintenance of a strategic reserve; and importation of maize to cover supply shortfalls. Single-channel marketing should be replaced by an internal free market operating between floor and ceiling prices by supply manipulation to prevent excessive producer and consumer welfare fluctuations. This system would be more efficient and have beneficial effects on development. It is more equitable for the rural poor, and result in greater stability of producer incomes, more reliable food supplies, higher producer prices and the release of public funds.     

Life expectancy of international cartels: An empirical analysis

This paper quantifies the importance of the various determinants of life expectancy for international cartels active throughout this century. I explain cartels' optimal duration as a function of market structure and demand growth and estimate the associated parameters recognizing that durability cannot be negative. According to the results, increases in either market shares or cartel concentration prolong life expectancy. Faster demand growth shortens cartel durability but this effect is not reliable. I also find that growth effects are sensitive to both the period of activity and the country coverage.The calculations in this paper use LIMDEP version 5.0. I am grateful to participants in seminars at the Federal Reserve Board and the U.S. International Trade Commission; to Alexander David, Jon Faust, Michael Gibson, William Greene, James Griffin, William Helkie, Dale Henderson, John Irons, Doug Irwin, Michael Leahy, Matthew Pritsker, Stephen Salant, and Janice Shack-Marquez for several suggestions. I also received very useful comments from two anonymous referees. The views expressed in this paper are solely the responsibility of the author and should not be interpreted as reflecting those of the Board of Governors of the Federal Reserve System or other members of its staff.     

Behind the scenes of the telecommunications miracle: An empirical analysis of the Indian market

The paper analyzes the demand and supply characteristics of the Indian telecommunications market, with the aim of contributing to the debate on the effectiveness of universal access policies in developing countries. The discussion is supported by some empirical evidence derived from a small time-series-cross-section dataset, containing mainly information on the fixed-lines segment of the market. The analysis suggests that the price elasticity of demand for fixed lines might be sensibly higher than the levels usually found in developed countries, while the crucial role of income and other sociodemographic variables seems to be confirmed. The paper also studies the impact of cellular penetration on fixed-lines diffusion. The results suggest the existence of a (positive) network effect in low penetration areas, while substitution (displacement) seems to arise in the most developed ones. Finally, the paper analyzes the supply side of the market, to assess the impact of market competition on investment. Competition seemingly helps stimulating investment in the most developed areas, but does not seem to have a significant impact in the less developed ones.