Annually million tons of freight and mail are being transported through US airports. The air freight transportation services reportedly result in millions of jobs, activities and dollars which in effect stimulate economic development of regions and the nation as a whole. Beyond passengers and aircraft movements, freight volume nowadays is another major target of opportunity for an airport manag...

Determining the optimal scale size of a combined cycle power plant is inherently a complex problem often with multiple and conflicting criteria as well as uncertain factors. The complexity of the problem is compounded by the production of undesirable outputs and the presence of natural and managerial disposability. We propose a customized data envelopment analysis (DEA) method for solving the r...

insurance industry is one of the most influential economic institutions and is considered to support other economic institutions and families. insurance industry has been facing changes that lead it to becoming a competitive industry. therefore, we can say insurance companies that are active in iran insurance industry must constantly monitor performance of their branches and agencies. ongoing p...

Frequently undesirable outputs are produced together with desirable. This joint production of bad and good outputs in connection with environmental decision models is the subject of this paper. Recently Haynes, Ratick, Bowen and Cummings-Saxton (1993) addressed the same subject matter. They observed that: "... input resources, including the chemicals of concern, produce as joint products the sa...

a r t i c l e i n f o Keywords: Malmquist–Luenberger index Urban water utilities Greenhouse gas emissions Nonparametric productivity measurement The energy use and greenhouse gas emissions in the provision of urban water and sewerage services have become an increasingly important issue in recent times. However, the impact of negative externalities such as greenhouse gas emissions on the product...

This research identifies returns to scale (RTS) of efficient decision making units (DMUs) with desirable (good) and undesirable (bad) inputs and outputs by presenting a new DEA (data envelopment analysis) approach. In this study, we first introduce a new input-output oriented model to determine efficient DMUs in the presence of undesirable factors and then, returns to scale of these DMUs are es...

The data envelopment analysis (DEA) technique is well known for computing the Malmquist-Luenberger productivity index (MLPI) in measuring change decision-making units (DMUs) over two consecutive periods. In this research, we detect infeasibility of directional distance function (DDF) based DEA model MLPI under variable returns to scale technology when takes on negative values. We address proble...