Original scientific paper
Including Exogenous Factors in the Evaluation of Harvesting Crew Technical Efficiency using a Multi-Step Data Envelopment Analysis Procedure
Okey Francis Obi
; University of Canterbury New Zealand School of Forestry 8041 Christchurch NEW ZEALAND
Rien Visser
; University of Canterbury New Zealand School of Forestry 8041 Christchurch NEW ZEALAND
Abstract
The performance of a harvesting crew in terms of its ability to transform inputs into outputs is influenced by discretionary factors within the unit’s control, such as the selection of machines and operators. However, factors associated with the operating environment, such as terrain slope and tree size that are outside the direct control of management, can also influence harvesting system efficiency. Using data on forest harvesting operations in New Zealand, this paper applies an established four-stage Data Envelopment Analysis (DEA) procedure to estimate the managerial efficiency of independent forest harvesting contractors, while taking into account the influence of the operating environment. The performance of 67 harvesting contractors is evaluated using seven inputs, one output (system productivity) and three operating environment factors in an input-oriented, variable return to scale DEA. The results show that the operating environment including terrain slope, log sorts and piece size influence the efficient use of inputs by harvesting contractors. A significant difference is observed between the mean managerial efficiency of the crews before and after controlling for the influence of the operating environment, the latter being higher by 11%. This study provides evidence that without accounting for the influence of the operating environment, the resulting DEA efficiency estimates will be biased; the performance of crews in favourable operating environment would be overestimated and those in unfavourable environment underestimated.
Keywords
data envelopment analysis; operating environment; forest harvesting; performance evaluation
Hrčak ID:
204180
URI
Publication date:
25.7.2018.
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