Suchergebnisse

This work studies the factors influencing the labor productivity of small and medium‐sized enterprises (SMEs) and large firms using Taiwan as a case study. A special emphasis is placed on two possible international channels: exports and foreign direct investment (FDI). Different from conventional studies, we employ the two‐stage switching regressions to correct the firm‐size effect on labor productivity and estimate labor productivity for SMEs and large firms. The main findings are as follows. First, the estimates of the selectivity variable are statistically significant for both SMEs and large firms, supporting the hypothesis of correcting the effect of firm‐size truncation. Second, while a larger trade intensity significantly increases the labor productivity of SMEs, it deteriorates significantly that of large firms. Third, FDI enhances the labor productivity of SMEs internally, whereas it has a negative spillover on that of other small and large firms in the industry. While the first outcome lends supports to the role of self‐selection, the remaining stands in sharp contrast to conventional wisdom.

AbstractAn optimization model which is frequently used to assist decision makers in the areas of resource scheduling, planning, and distribution is the minimum cost multiperiod network flow problem. This model describes network structure decision‐making problems over time. Such problems arise in the areas of production/distribution systems, economic planning, communication systems, material handling systems, traffic systems, railway systems, building evacuation systems, energy systems, as well as in many others. Although existing network solution techniques are efficient, there are still limitations to the size of problems that can be solved. To date, only a few researchers have taken the multiperiod structure into consideration in devising efficient solution methods. Standard network codes are usually used because of their availability and perceived efficiency. In this paper we discuss the development, implementation, and computational testing of a new technique, the forward network simplex method, for solving linear, minimum cost, multiperiod network flow problems. The forward network simplex method is a forward algorithm which exploits the natural decomposition of multiperiod network problems by limiting its pivoting activity. A forward algorithm is an approach to solving dynamic problems by solving successively longer finite subproblems, terminating when a stopping rule can be invoked or a decision horizon found. Such procedures are available for a large number of special structure models. Here we describe the specialization of the forward simplex method of Aronson, Morton, and Thompson to solving multiperiod network network flow problems. Computational results indicate that both the solution time and pivot count are linear in the number of periods. For standard network optimization codes, which do not exploit the multiperiod structure, the pivot count is linear in the number of periods; however, the solution time is quadratic.

Improper domestic food handling in rural areas of China is an important public health issue leading to foodborne illness. However, the underlying factors responsible for poor domestic food hygiene practices have not been comprehensively studied. Here, a cross-sectional study was conducted in Anhui Province, China between 2015 - 2016, using a questionnaire to collect data from 819 respondents, selected using multistage cluster random sampling techniques. Multivariate logistic regression analysis was then used to assess the demographic factors associated with improper food handling. Results showed that 525 (64.1%) of respondents used improper food handling techniques. The factors associated with improper food handling included gender, age, education, income, and occupation. Males (vs. females), adults aged ≥ 50 years (vs. those aged 18 - 30 years), individuals with primary school education or lower (vs. individuals with a bachelor's degree or higher), individuals with annual incomes of < 4,387 USD (vs. income ≥ 13,161 USD), and workers (vs. other occupation groups) were more likely to report inappropriate food handling practices in rural areas. The results obtained from the present work may provide the basis for training in domestic food safety hygiene/handling practices in rural areas of China in order to reduce the incidence of foodborne illnesses.