A Note on an Economic Lot-sizing Problem with Perishable Inventory and Economies of Scale Costs:Approximation Solutions and Worst Case Analysis

This paper presents an economic lot-sizing problem with perishable inventory and general economies of scale cost functions. For the case with backlogging allowed, a mathematical model is formulated, and several properties of the optimal solutions are explored. With the help of these optimality properties, a polynomial time approximation algorithm is developed by a new method. The new method adopts a shift technique to obtain a feasible solution of subproblem and takes the optimal solution of the subproblem as an approximation solution of our problem. The worst case performance for the approximation algorithm is proven to be （4√2 ＋ 5）/7. Finally, an instance illustrates that the bound is tight.

Scale and scope economies in small household rice farming in Vietnam

The Vietnamese agricultural sector has experienced a dramatic structural change based on increased specialization in rice cultivation.However,small-scale rice-farmers have continued to grow multiple crops,especially in less developed provinces.While the literature advocates crop diversification for reasons of both economic and ecological sustainability,there lacks empirical evidence as to whether crop diversification brings efficiency and productivity gains to small farms.The present study is the first applications of the input-oriented stochastic distance function approach in estimating scale and scope economies using data of multi-crop farming households in Vietnam.We find strong evidence of product-specific economies of scale.Scope economies are also present for rice,vegetable,and other annual crop production.This suggests that crop diversification enhances efficiency and productivity.However,there still exists significant technical inefficiency in crop production,indicating opportunities to expand farm output at the existing level of inputs and technologies.More specifically,our empirical results indicate that it is desirable to expand vegetable and other annual crop production in mountainous areas while rice cultivation can be further expanded in delta and coastal regions.

China＇s Agricultural Modernization and Economies of Scale： Barriers and Solutions

This paper identifies three stages in China's agricultural development with reference to macroeconomic development and international experience.While the first two stages focused on ensuring food security and raising farmer's income,the current stage must give priority to modernizing agricultural production.The lack of progress in this area is due to the following reasons:diminishing return to capital as a result of small and scattered farming operation which has compromised agricultural competitiveness;agriculture is overdependent on subsidy and protection under the conventional wisdom of the uniqueness of agriculture.This paper attempts to reveal the barriers to China s agricultural modernization and proposes recommendations on reforming the land and household registration systems to increase the economies of scale and productivity.

Data envelopment analysis for scale elasticity measurement in the stochastic case:with an application to Indian banking

In the nonparametric data envelopment analysis literature,scale elasticity is evaluated in two alternative ways:using either the technical efficiency model or the cost efficiency model.This evaluation becomes problematic in several situations,for example(a)when input proportions change in the long run,(b)when inputs are heterogeneous,and(c)when firms face ex-ante price uncertainty in making their production decisions.To address these situations,a scale elasticity evaluation was performed using a value-based cost efficiency model.However,this alternative value-based scale elasticity evaluation is sensitive to the uncertainty and variability underlying input and output data.Therefore,in this study,we introduce a stochastic cost-efficiency model based on chance-constrained programming to develop a value-based measure of the scale elasticity of firms facing data uncertainty.An illustrative empirical application to the Indian banking industry comprising 71 banks for eight years(1998–2005)was made to compare inferences about their efficiency and scale properties.The key findings are as follows:First,both the deterministic model and our proposed stochastic model yield distinctly different results concerning the efficiency and scale elasticity scores at various tolerance levels of chance constraints.However,both models yield the same results at a tolerance level of 0.5,implying that the deterministic model is a special case of the stochastic model in that it reveals the same efficiency and returns to scale characterizations of banks.Second,the stochastic model generates higher efficiency scores for inefficient banks than its deterministic counterpart.Third,public banks exhibit higher efficiency than private and foreign banks.Finally,public and old private banks mostly exhibit either decreasing or constant returns to scale,whereas foreign and new private banks experience either increasing or decreasing returns to scale.Although the application of our proposed stochastic model is illustrative,it can be potentially applied to all firms in the information and distribution-intensive industry with high fixed costs,which have ample potential for reaping scale and scope benefits.

Can whole steps of grain production be outsourced? Empirical analysis based on the three provinces of Jiangsu,Jilin,and Sichuan in China

Certain outsourcing services for agricultural management in China,such as pest control in grain production,have experienced prolonged sluggishness,contrasting with the relatively high level of outsourcing services observed in harvesting,land preparation,and sowing.This study examines the feasibility of implementing whole-step outsourcing in grain production by conducting a case study of rice and maize production in Jiangsu,Jilin,and Sichuan provinces in China.The provision of outsourcing services hinges on two essential conditions:technological advancements fostering specialized production and economies of scale,coupled with a market size sufficient to realize the aforementioned potential economies of scale.The results showed that outsourcing pest control or harvesting services had varying economies of scale.The outsourcing services in pest control were less common than in harvesting services,and their marginal growth space of the economies of scale with technological change was also smaller.Determined by the operational characteristics of pest control itself,the market scale of its professional services is small.Therefore,achieving the whole-step outsourcing of grain production necessitates not only technological innovation but also effective policy interventions to overcome the constraints of market scale.Such interventions include(1)optimizing crop layouts between planning regions and reducing land fragmentation and(2)supplying timely and effective inter-regional agricultural information for service providers aided by information technology.

The Rice Processing Industry in Nepal: Constraints and Opportunities

A rice mill survey covering diverse rice processing companies in terms of their milling output, type of technology and year of establishment was conducted to understand the current situation of the rice milling industry and to identify enablers and barriers to its growth in Nepal. Coarse rice varieties dominate Nepal’s rice processing industry, with a 42% share by total weight, followed by medium rice (34%) and fine varieties (less than 7%). Polished white rice (Arwa) was the dominant rice type in Nepal in the survey, followed by parboiled and steamed rice. The price and profit margins increased from coarse to fine rice varieties and from Arwa to parboiled and steamed rice. The cost of milling also followed a similar trend. The rice milling industry in Nepal largely influences the adoption or non-adoption of any specific type of rice variety by dictating specific brands in the market and this has important implications for rice research and development. The rice processing industry of Nepal was unable to compete with the Indian rice milling industry because of: 1) low profit margins due to the high cost of rice production and procurement, 2) a lack of economies of scale, 3) a lack of milling technologies for long and extra-long and steamed rice in the country and a lack of investment to modernize rice milling technology, and 4) unavailability of paddy throughout the year locally. Millers were willing to upgrade their rice milling technology to include high throughput parboiling, steamed rice as well as long and extra-long grain rice. This will be a strategic decision in counteracting the ever-increasing rice imports in Nepal. We believe that the findings of the study will be vital for formulating an appropriate rice research, development and rice processing strategy for Nepal to achieve food and nutritional security and the Sustainable Development Goals.

Techno-Economic Assessment of Non-Revenue Water: A Case Study at AER, GWCL

This study utilizes multiple regression analysis and the technique for computing economies of scale to evaluate the dynamics of NRW in the AER of GWCL. Data on monthly total production, billed consumption, total revenue, total production cost and the volume of NRW spanning the period January 2015 to June 2019, was obtained from the headquarters of AER and used for the analysis. The study showed that NRW averaged 59.3% for the period under consideration, which far exceeds the 25% threshold set by the World Bank for developing economies. It was also established that a fairly inelastic relationship exists between NRW and total revenue. Results further show that resources are not optimally used in the AER as proof of diseconomies of scale was observed.

Productivity Change and Growth in Posts and Telecommunications Sector

First,the Production Functions(PF)are estimated for Posts and Telecommunications(P&T)sector's aggregate economy, using annual data from 1957 to 1993. In this paper the contributions of factorinputs to the output growth are measured.Some comparative static results are presented and some interesting results about the economic characteristics of P&T sector are introduced.

Examining export trade and corporate innovation:A multiphase difference-in-differences method

Using a multiphase difference-in-differences model, this study investigates the relationship between export trade and the corporate technological innovation of listed companies. It reveals that engaging in export trade increases corporate innovation input and output. In terms of patent output, export trade greatly promotes the output of invention patents and utility model patents with a high technological content. These conclusions remain valid after a series of robustness and endogeneity tests. Regarding the mechanisms of the observed relationships, export trade stimulates corporate technological innovation mainly by realizing economies of scale and increasing risk-taking. The positive correlation between export trade and corporate technological innovation is strongest among state-owned enterprises, non-high-tech enterprises, enterprises based in central and eastern China, enterprises engaged in general trade, and enterprises exporting to developed economies. Given the growing trade frictions ongoing at the time of writing, the conclusions of this study provide vital practical guidance and empirical evidence for a national strategy of innovation-driven development.