برآورد شاخص درست هزینه زندگی و شاخص درست درآمد واقعی برای خانوارهای روستایی ایران
محورهای موضوعی : فصلنامه اقتصاد محاسباتی
شهرام فاتح عسگرخانلو
1
,
علی اکبر خسروی نژاد
2
,
شهریا ر نصابیان
3
,
سید نعمت اله موسوی
4
1 - گروه اقتصاد، دانشکده اقتصاد و حسابداری، دانشگاه آزاداسلامی واحد تهران مرکزی، تهران، ایران
2 - Faculty Of Economic and Accounting, Islamic Azad University Central Tehran Branch
3 - گروه اقتصاد نظری، واحد تهران مرکزی، دانشگاه آزاد اسلامی، تهران، ایران
4 - Department of Agricultural Economics, Islamic Azad University, Marvdasht Branch, Marvdasht, Iran
کلید واژه: شاخص درست هزینه زندگی, شاخص درست درآمد واقعی, سیستم مخارج خطی, خانوارهای روستایی,
چکیده مقاله :
اندازهگیری دقیق تغییرات رفاهی و قدرت خرید خانوار، سنگبنای تحلیل سیاستهای عمومی و بهویژه برنامههای حمایتی بخش کشاورزی است. ارزیابی درست این سیاستها مستلزم شاخصی است که بتواند اثرات واقعی تغییرات قیمت و درآمد را بر مطلوبیت خانوارها منعکس کند. ادبیات اقتصاد رفاه بر استفاده از شاخصهای مبتنی بر نظریه تقاضا برای رفع این محدودیت تأکید دارد.
در این چارچوب، مقاله حاضر با بهرهگیری از دادههای بودجه خانوار و برآورد سیستم مخارج خطی با عادت نسبی، به محاسبه شاخص درست هزینه زندگی و برای نخستین بار، شاخص درست درآمد واقعی برای خانوارهای روستایی ایران طی سالهای ۱۳۸۳ تا ۱۴۰۲ میپردازد. برآورد کششهای درآمدی نشان میدهد که خوراکیها (0.83) و مسکن (0.81) کالاهای ضروری بودهاند، در حالی که کشش درآمدی بزرگتر از یک برای حملونقل (1.24) و «سایر کالاها» (1.38) نشاندهنده لوکس بودن نسبی آنها است.
محاسبه شاخصهای رفاهی نشان میدهد شاخص درست هزینه زندگی در این دوره بیش از ۷۰ برابر افزایش یافته است. در مقابل، شاخص درست درآمد واقعی نشاندهنده کاهش تقریباً ۵ درصدی قدرت خرید خانوارهای روستایی در سال ۱۴۰۲ نسبت به سال پایه ۱۳۹۵ است.
بر مبنای این نتایج، استفاده از شاخصهای رفاهی مبتنی بر رویکرد اقتصادی ـ بهویژه شاخص درست هزینه زندگی و شاخص درست درآمد واقعی ـ بهعنوان مبنایی دقیقتر در محاسبه جبران خسارت ناشی از سیاستهای تعدیل قیمت، ارزیابی آثار سیاستهای حمایتی، تعیین دستمزد و طراحی پرداختهای انتقالی توصیه میشود.
Extended Abstract
Purpose
Accurate measurement of changes in household welfare and purchasing power is the cornerstone of public policy analysis, particularly for agricultural support programs. A proper evaluation of these policies requires indices that can reflect the real effects of price and income changes on household utility. The welfare economics literature emphasizes the use of demand theory-based indices to overcome the shortcomings of fixed-basket approaches, which fail to account for optimal consumer behavior, particularly substitution effects in response to changes in relative prices. This study, operating within this theoretical framework, aims to estimate the True Cost of Living Index (TCLI) and, for the first time, the True Index of Real Income (TIRI) for rural households in Iran. By doing so, it provides a more robust foundation for assessing the welfare impacts of support policies, setting wages, and designing transfer payments for this crucial demographic.
Methodology
The study is grounded in the theory of cost-of-living indices initiated by Konüs (1924) and advanced by Hicks (1940), who established the direct link between index numbers and utility theory. The core methodology involves estimating a dynamic Linear Expenditure System (LES) with relative habit formation, a model pioneered by Stone (1954). The habit formation hypothesis posits that the minimum subsistence level for a good in the current period is a function of its consumption in the previous period , formally defined as .
The model was estimated using Feasible Generalized Nonlinear Least Squares (FGNLS) on official annual data from the Statistical Center of Iran (2003–2024), specifically the Household Expenditure and Income Survey for rural areas and the corresponding Rural Consumer Price Index, for eight consumption groups. The empirical share equation for the LES with habit formation is:
where , is the budget share, is total expenditure, is the habit parameter, and is the marginal share of supernumerary expenditure. The TCLI and TIRI were then derived analytically from the estimated system. Unit root tests on the residuals confirmed the existence of stable long-run relationships among the variables.
Findings
Model Estimation and Elasticities The model was successfully estimated for six goods groups (one equation was dropped to satisfy the adding-up condition). All estimated income elasticities were positive. Food (0.83) and Housing (0.81) were identified as necessities (income elasticity < 1), while Transportation (1.24) and "Other Goods and Services" (1.38) were classified as relative luxuries (income elasticity > 1). All own-price elasticities were negative and inelastic (less than 1 in absolute value), with Clothing being the least elastic (-0.343) and "Other Goods" the most (-0.549). This indicates that rural consumers are relatively insensitive to price changes for these goods, particularly for basic necessities.
Calculation of Welfare Indices The computed TCLI and TIRI, based on two different base years (2004 and 2016), reveal robust and consistent trends independent of the base year choice.
- True Cost of Living Index (TCLI): The TCLI exhibited a dramatic and continuous upward trend over the two decades, increasing more than seventyfold from 12 in 2004 to over 844 in 2023 (base 2016=100). The rate of increase accelerated significantly after 2017, indicating a substantial and growing cost-of-living pressure on rural households to maintain a constant level of
- True Index of Real Income (TIRI): The TIRI presents a more nuanced picture of After a period of relative improvement peaking in 2005 (149.9, base 2016=100), it began a gradual decline from around 2016-2017 onwards. By 2023, the TIRI had fallen to 95.0, revealing an approximate 5% decline in the real purchasing power of rural households compared to the base year 2016. This decline, hidden by conventional indices, signals a gradual erosion of rural welfare since the mid-2010s.
The simultaneous surge in the TCLI and the fall in the TIRI after 2016 creates a widening "welfare gap," visually demonstrating the intensifying economic pressure on rural households.
Conclusion
This study provides the first comprehensive estimation of both the True Cost of Living Index and the True Index of Real Income for rural households in Iran. The findings unequivocally demonstrate the superiority of these theoretically grounded indices over traditional measures for welfare analysis. The identified trends—soaring living costs and declining real income—paint a concerning picture of the economic well-being of rural Iran in recent years.
Based on these results, the following policy recommendations are proposed:
- Targeted Subsidies and Transfers: Given that increased income is primarily spent on necessities like food and housing, direct cash transfers or subsidies targeted specifically at these essential goods are likely to be highly effective in bolstering food security and basic livelihoods for rural
- Official Adoption of Advanced Indices: Official statistical authorities should prioritize the calculation and regular publication of theory-based welfare indices like the TCLI and This would provide a more accurate foundation for wage indexation, transfer payment adjustments, and subsidy targeting, preventing resource misallocation.
- Compensatory Social Policies: The documented decline in real purchasing power, particularly post-2016, calls for strengthened and well-targeted compensatory social protection These should be designed based on accurate welfare metrics to effectively reach the most vulnerable rural households.
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