Home | << 1 >> |
Alves, P. N., Melo, I. C., Santos, R. D., da Rocha, F. V., & Caixeta, J. V. (2022). How did COVID-19 affect green-fuel supply chain? – A performance analysis of Brazilian ethanol sector. Res. Transp. Econ., 93, 101137.
Abstract: The COVID-19 pandemic affected many supply chains worldwide, including the Brazilian green-fuel ethanol supply chain. Our analysis considered sustainability variables (social, environmental, and economic) to investigate the pandemic's effects on the ethanol industries of 15 ethanol producing Brazilian states, comparing data from 2020 to 2019 and applying a novel Data Envelopment Analysis (DEA): the Double Frontier Slack-Based Measure Malmquist Productivity Index (DF-SBM MPI). The findings show that all states suffered negative impacts from the pandemic and some incurred a risk of collapsing it. The least negatively impacted states were Sao Paulo and Mato Grosso. Sao Paulo's ethanol sector is a benchmark for income derived from trade in carbon-credits by RenovaBio certified mills, while Mato Grosso's sector is able to take advantage of the largest spread between ethanol and gasoline prices, certainly a competitive advantage for ethanol producers. We recommend the implementation of public policies to support, mainly, the most affected states by assisting their mills to become environmentally certified participants to take advantage of income opportunities available in the carbon-credit trading market. We recommend, among other actions, a temporary ethanol sales tax reduction, an extension of debt repayment schedules, and stimulating an increase in the fleet of flex-fuel vehicles.
|
Junior, P. N. A., Melo, I. C., Yamanaka, L., Severino, M. R., & Rentizelas, A. (2022). Supporting the Bidding Decisions of Smallholder Farmers in Public Calls in Brazil. Agriculture, 12(1), 48.
Abstract: In Brazil, the National School Feeding Program (PNAE) seeks to contribute to the socio-economic development of smallholder farmers, prioritizing them in supplying their products for preparing daily meals in public schools. However, farmers face challenges in determining which school calls to bid for and the potential benefits from their participation, due to the multiple quantitative and qualitative decision criteria involved. This paper presents a novel Data Envelopment Analysis (DEA)-based method for bidding priority setting, to support the decision making. The model was applied for a case study in Brazil. The academic contribution lies in the innovation of using a Double-Frontier Slack-Based Measure (SBM) DEA model for Hierarchical Network systems, i.e., applied to multiple levels and followed by a tie-breaking method. The practical contribution lies in the decision support of farmers by presenting the results at three levels, the first of which is a ranking by the town or urban cluster priority, the second by the school, and the third by the products. Thus, using the rankings of calls, farmers can make informed decisions regarding the feasibility of bidding for each PNAE public call. At the same time, the objective rankings can alleviate friction and conflict within co-operatives during the decision-making process.
|
Yushimito, W. F., Alves, P. N., Canessa, E., & de Mateo, F. (2018). Relating Efficiency With Service Compliance Indices In Public Transportation Using Slack-Based Measure Data Envelopment Analysis And Shadow Prices. Promet, 30(6), 661–670.
Abstract: In many countries, bus operators are private companies whose service has been leased by government agencies. These agencies develop service compliance indices or measures to keep track of factors such as passenger satisfaction, frequency, and regularity but do not necessarily include the objectives of the operators in the assessment. In this paper, we used slack-based measure data envelopment analysis (SBM) to investigate whether it is possible for a bus operator to be efficient (from a private perspective) and match required standards of frequency and regularity. In doing so, data collected from two major bus operators in Santiago, Chile has been used comprising 99 services. The results show that when private objectives, namely revenues, are included in the analysis, bus operators do not necessarily seek to improve the regularity of their service. Moreover, it was found that some bus services are on the efficient frontier while keeping low performance measure standards. Using the shadow prices of the models, it was also found that improving the performance measures will be hard for many bus services unless there is a significant change in factors that are not under control of the operators (i.e., number of stops, length of the route, etc.). This shows the difficulty of correctly aligning the private objectives of operators with agencies' objectives.
|
Yushimito, W. F., Holguin-Veras, J., & Gellona, T. (2018). Firm's efficiency and the feasibility of incentives for flextime adoption: a preliminary analysis of Chilean employer's response. Transp. Lett., 10(4), 202–214.
Abstract: Flextime is a Travel Demand Management policy that allows workers to arrive/leave within a certain threshold of time but staying on duty during a period of the day (core hours). Such flexibility in arrival time can have an impact on relieving traffic congestion as it can shift demand to nonpeak periods. However, in several countries, companies are usually reluctant to provide flexibility arguing possible loss in their productivity and efficiency. This paper discusses a preliminary study on perceptions of challenges, and the potential of flextime in congested urban areas. In doing so, we present the information gathered through in-depth-interviews and subsequent questionnaires applied to managers of cars dealers in Santiago, Chile, obtaining both qualitative and quantitative information. The quantitative information obtained was used to develop (1) a data envelopment analysis to investigate whether firms' productivity is affected by flextime or not, and (2) a binary logit model to evaluate financial and non-financial incentives that can allow firms to adopt flextime or change work arrival times. The results obtained from the sample show that, for this particular industry, flextime might not have a significant impact on firms' productivity. Additionally, we found that financial incentives and competitors' work starting times have a significant impact on accepting flextime or relaxing arrival constraints. We also found that if arrangements with the whole industry to change work starting times are made, the effect of this change can be as effective as the provision of financial incentives.
|