Iranian Journal of Trade Studies

Iranian Journal of Trade Studies

Measuring Economies of Scale, X-inefficiency, and Welfare Costs of Monopoly in Selected Iranian Industries

Document Type : Research Paper

Authors
1 Department of Economics, Shi.C., Islamic Azad University, Shiraz, Iran.2470887682@iau.ir
2 ,Department of Economics, Shi.C., Islamic Azad University, Shiraz, Iran
3 Department of Economics, Shi.C., Islamic Azad University, Shiraz,Iran
Abstract
This research aims to measure economies of scale, welfare costs resulting from monopoly, and the extent of X inefficiency during the period 2002 to 2022. The study uses panel data from 38 industries and applies the Liebenstein–Comanor method to calculate the welfare cost of monopoly, along with a Translog cost function to estimate X inefficiency and economies of scale.
The findings reveal three structural crises. First, economies of scale have been declining and fell to about one quarter of their peak value (0.029 in 2012) by 2022, indicating a loss of the advantages of large scale production. Second, the welfare cost of monopoly has been increasing, nearly doubling within only two years (2020 to 2022). This cost is mainly concentrated in basic industries such as steel, automotive, and petrochemicals. Third, X inefficiency (resource waste within firms) has been rising, increasing from 0.301 to 0.351, which indicates a growth in managerial inefficiency. Accordingly, the article emphasizes separating firms with significant market power, expanding public ownership through public investment funds, and improving price transparency as measures to reduce monopoly power. At the same time, it highlights smart mergers and clustering among small and medium sized enterprises as mechanisms to strengthen economies of scale and enhance industrial competitiveness.
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Articles in Press, Accepted Manuscript
Available Online from 01 September 2026

  • Receive Date 01 February 2026
  • Revise Date 18 July 2026
  • Accept Date 28 July 2026