Environmental efficiency of the Indian cement industry: An interstate analysis

Purpose Cement as one of the major components of construction activities, releases a tremendous amount of carbon dioxide (CO2) into the atmosphere, resulting in adverse environmental impacts and high energy consumption. Increasing demand for CO2 consumption has urged construction companies and decision-makers to consider ecological efficiency affected by CO2 consumption. Therefore, this paper aims to develop a method capable of analyzing and assessing the eco-efficiency determining factor in Iran’s 22 local cement companies over 2015–2019. Design/methodology/approach This research uses two well-known artificial intelligence approaches, namely, optimization data envelopment analysis (DEA) and machine learning algorithms at the first and second steps, respectively, to fulfill the research aim. Meanwhile, to find the superior model, the CCR model, BBC model and additive DEA models to measure the efficiency of decision processes are used. A proportional decreasing or increasing of inputs/outputs is the main concern in measuring efficiency which neglect slacks, and hence, is a critical limitation of radial models. Thus, the additive model by considering desirable and undesirable outputs, as a well-known DEA non-proportional and non-radial model, is used to solve the problem. Additive models measure efficiency via slack variables. Considering both input-oriented and output-oriented is one of the main advantages of the additive model. Findings After applying the proposed model, the Malmquist productivity index is computed to evaluate the productivity of companies over 2015–2019. Although DEA is an appreciated method for evaluating, it fails to extract unknown information. Thus, machine learning algorithms play an important role in this step. Association rules are used to extract hidden rules and to introduce the three strongest rules. Finally, three data mining classification algorithms in three different tools have been applied to introduce the superior algorithm and tool. A new converting two-stage to single-stage model is proposed to obtain the eco-efficiency of the whole system. This model is proposed to fix the efficiency of a two-stage process and prevent the dependency on various weights. Converting undesirable outputs and desirable inputs to final desirable inputs in a single-stage model to minimize inputs, as well as turning desirable outputs to final desirable outputs in the single-stage model to maximize outputs to have a positive effect on the efficiency of the whole process. Originality/value The performance of the proposed approach provides us with a chance to recognize pattern recognition of the whole, combining DEA and data mining techniques during the selected period (five years from 2015 to 2019). Meanwhile, the cement industry is one of the foremost manufacturers of naturally harmful material using an undesirable by-product; specific stress is given to that pollution control investment or undesirable output while evaluating energy use efficiency. The significant concentration of the study is to respond to five preliminary questions.

Environmental efficiency and economic growth of China: A Ray slack-based model analysis

An integrated approach of discrete event simulation and a non-radial super efficiency data envelopment analysis for performance evaluation of an emergency department

The concept of congestion, which is mainly applied in economics, refers to a situation where inputs are overinvested. Many studies have focused on congestion measurement by means of data envelopment analysis (DEA). However, most of the previous investigations only considered the framework of desirable outputs. In fact, firms in the real world unavoidably generate undesirable outputs (such as pollutants or wastes) along with desirable outputs. Therefore, a new scheme is required for measuring congestion in the simultaneous presence of both desirable and undesirable outputs. This paper develops a nonradial efficiency measure for including undesirable outputs into the environmental performance. Based on the proposed model, a new definition and a new approach are presented to deal with congestion in the simultaneous presence of desirable and undesirable outputs. Then, this paper uses the presented method to study the pollutants (waste gas emission and waste discharge) of 31 administrative regions of China. The finding indicates that 7 industries pay attention to the reduction of their pollutants accompanying improvement of their commercial targets. Consequently, they do not show congestion in any input.

Efficiency measurement of Chinese airports with flight delays by directional distance function

Environmental efficiency has become a key indicator in describing the capacity of regional resource utilization with consideration of the negative externality to nature. Notably, with the development of urban agglomerations all over the world, the role and strategy of efficiency measurement for cities should be reorganized to deal with the complex relationships among cities based on urban agglomerations. In this paper, we construct a set of data envelopment analysis (DEA) models based on a peer-evaluation mode with consideration to the cooperative relationships among cities within the same urban agglomeration together with the competitive relationships between different urban agglomerations. Then, this paper we analyze the environmental efficiency of 48 Chinese mainland cities belonging to the Beijing-Tianjin-Hebei Urban Agglomeration (BTHUA), Yangtze River Delta Urban Agglomerations (YRDUA), and Guangdong-Hong Kong-Macao Greater Bay Area (GHMGBA). This was accomplished during 2014 to 2019 by using four inputs, two desirable outputs, and two undesirable outputs. The results of efficiency scores indicate that the environmental efficiency trend increased during the time series from 2014 to 2019 while the difference on environmental efficiency among different cities and urban agglomerations are significant. The BTHUA is the best performing urban agglomeration with much higher environmental efficiency scores in all the years. Besides, this paper selected 11 influencing factors based on three different angles to analyze the internal and external environments to environmental efficiency scores for providing further inspiration to managers.

DEA approach for unified efficiency measurement: Assessment of Japanese fossil fuel power generation

DEA environmental assessment of coal fired power plants: Methodological comparison between radial and non-radial models

Returns to Scale and Damages to Scale with Strong Complementary Slackness Conditions in DEA Assessment: Japanese Corporate Effort on Environment Protection

Data Envelopment Analysis (DEA) model usually does not consider the interaction between the decision making units (DMU). The interaction can be represented in the form of two consecutive stages in which the outputs from the precedent stage will be the inputs for the latter stage. The two consecutive stage DEA model can be represented as Non-separable DEA (NS-DEA) which integrates both desirable and undesirable output. The undesirable output unlike desirable output, indicates a higher efficiency if the output is lower or not productive. The different orientation between desirable and undesirable output may affect the efficiency score especially if it was formed in two consecutive stages. Thus, this research attempts to address four different types of dependence relationship which can occur in the formation of two consecutive stage DEA models and to investigate the impact towards the overall efficiency of the DMUs. The finding shows that the determination of positive or negative correlation between the two stages which combines both desirable and undesirable output, are more likely to be influenced by the orientation of the first precedent stage.

Study of energy strategy by evaluating energy–environmental​ efficiency

Undesirable factors in integer-valued DEA: Evaluating the operational efficiencies of city bus systems considering safety records

This study employs four data envelopment analysis (DEA) models to evaluate the performance efficiency of 21 OECD countries and assess whether the undesirable outputs are over-produced relative to desirable outputs. In evaluating the performance of OECD countries via super-efficiency models, this study focuses on two aspects. First, employing the concept of the Sharpe ratio, we propose another method to deal with undesirable outputs (the unemployment rate, inflation, and air pollution) in DEA. This approach can reveal the relative importance of desirable outputs and undesirable outputs, detect whether undesirable outputs are over-produced, and obtain more accurate efficiency scores. Second, we examine whether knowledge capital can improve a country’s efficiency scores. Our empirical results support the above arguments. In addition, research and development (R&D) expenditures, the proxy variable for knowledge capital, can indeed improve countries’ efficiency scores, implying that the endogenous growth theory is supported in OECD countries. Evidently, whether the undesirable outputs are included in the DEA models and are properly treated is crucial in the evaluation of efficiency values.

Maritime transport relies on a large amounts of fossil fuels. It provides cargo-carrying services but simultaneously emits enormous amounts of by-products such as CO2, which cause climate change. The IMO has adopted mandatory measures to reduce the shipping industry’s greenhouse gas emissions by at least 70% by 2050, relative to 2008. In this paper, we select 11 liner shipping companies as decision-making units (DMUs) that account for more than 80% of the world’s shipping capacity. Utilizing the directional distance function, we estimate their environmental efficiency in 2019, 2020, and 2021. The directional vector serves to expand desired outputs and contract undesirable outputs. The larger the distance, the farther the evaluated unit is from the production frontier, and the less environmentally efficient it is assessed. This study compares the impact of environmental regulations on liner shipping based on two methods of dealing with undesirable outputs. Since the results indicate the low overall environmental efficiency of liner shipping, firms should strengthen their decarbonization efforts to achieve environmental efficiency goals. Moreover, the results also demonstrate that environmental regulations significantly impact liner shipping companies and that they need to reduce by-product outputs to comply with regulations.

The enhanced Russell-based directional distance measure with undesirable outputs: Numerical example considering CO2 emissions