تاثیر یکپارچه‌سازی بر کارایی شرکت‌های آب و فاضلاب با استفاده از روش تحلیل پوششی داده‌ها

شرکت‌های آب و فاضلاب (آبفا) تامین کننده یکی از مهمترین خدمات لازم برای تامین رفاه و بهداشت  جامعه‌اند. در ایران قبلا فعالیت این شرکت‌ها در مناطق شهری و روستایی به طور مجزا تعریف شده بود و در هر استان شرکت آبفا روستایی به نواحی روستایی و شرکت آبفا شهری به مناطق شهری خدمات ارائه می‌کرد. به منظور افزایش کارایی این بخش، در سال 1398 به موجب قانون، شرکت‌های آبفا روستایی به شرکت‌های آبفا شهری ملحق و شرکت‌های یکپارچه استانی تشکیل شد. در نتیجه، ساختار این شرکت‌ها در هر استان از نظر تشکیلاتی و مقیاس فعالیت دچار تغییر شد. به منظور بررسی اثرات این تغییر، در این پژوهش وضعیت کارایی شرکت‌های آب و فاضلاب در هر استان قبل و بعد از یکپارچه سازی مقایسه شده است. برای این کار از روش ناپارامتریک تعیین کارایی بنگاه به صورت تحلیل پوششی داده‌ها (dea) با مدل بازدهی متغیر به مقیاس (vrs) استفاده شد. دو عامل «میزان دارایی‌ها» و«نیروی کار»  شرکت به عنوان داده و «تعداد انشعابات آب» و «تعداد انشعابات فاضلاب» به عنوان ستاده در نظر گرفته شده‌اند و کارایی شرکت‌های آب و فاضلاب کل کشور شامل 31 استان و 3 شرکت مستقل در قبل و بعد از  یکپارچگی بررسی شده است. نتایج نشان داده است: میانگین وزنی کارایی شرکت‌ها از 0.66 در سال 1397 به 0.75 در سال 1400 رسیده است یعنی یکپارچه سازی میزان کارایی مجموعه آب و فاضلاب را بالا برده است.

efficiency effect of unification on iranian water and wastewater companies using data envelopment analysis

water utilities provide one of the most crucial services to boost the health and welfare of communities. in iran, urban and rural water utilities operated independently until 2019,  with separate entities serving each province’s urban and rural populations. to enhance efficiency in 2019 by law the rural water utilities were attached to the urban ones and provincial unified water utilities were formed. for water utilities, this brought about enormous changes in terms of organizational structure and scale of operation. in order to determine the efficiency effects of the change, this paper compares the efficiency of water utility services in each province before and after the unification. to do so, a non-parametric method for measuring efficiency in the form of data envelopment analysis (dea), with variable returns to scale (var) was used. “labor forces” and “assets” of the companies were taken as inputs, and “number of water connections” and the “number of wastewater connections” as outputs and the effects of the changes in the efficiency of all 31 provincial and 3 independent water utilities before and after unification were compared. results show that the weighted average of efficiency in the whole water and wastewater sector was improved from .66 in 2018 to .75 in 2021, and unification has improved the average efficiency score in the water utility sector in iran.introductionin iran, until 2019 water and wastewater utilities used to deliver water and sanitation services separately as different urban water utilities and rural water utilities. hence in each province, there existed two different water utilities. in 2019 by law the rural water utilities were attached to the urban ones and provincial unified water utilities were formed. the unification was an enormous change in terms of organizational structure and scale of operation for water and wastewater services in the country. to determine the efficiency effects of the change, we compared the efficiency of water utility services in each province before and after the unification. specifically, we were to answer the following question:did the unification of water utilities improve efficiency in the sector?methods and materialfor efficiency measurement in economic firms as decision-making units, there are different ways among which data envelopment analysis (dea) is one of the most popular. to answer the above question, the non-parametric method for measuring efficiency in the form of data envelopment analysis (dea) was used. since a water and wastewater utility is a natural monopoly and there exist increasing returns to scale, we assumed variable returns to scale (var). among many other inputs in a water and wastewater utility, and similar to the explanation of production functions in most of the studies, we used “labor forces” and “assets” of the companies for inputs as the proxies for labor and capital. for output, the issue is more sophisticated since namely, only the water distributed and wastewater collected are the final products. but in a country as big and diverse as iran, much more can be regarded as output instead of water distributed and wastewater collected. the utilities have a lot to do to reach the final product any of which could be regarded as a proxy for the final product. these include “total water distributed”, “total wastewater collected”, “length of distribution network”, “number of water or wastewater connections”, “number of water or wastewater purification plants” and so on. since the total water distributed is a function of water demand by water connections, and also it is affected by water resources available for the utilities to distribute, it seems that the best variables to take as the output are “number of water connections” and the “number of wastewater connections”