Gelir vergisi tarifelerinin ekonomik etki analizi: Türkiye için bir sosyal hesaplar matrisi modellemesi
Economic impact analysis of income tax schedules: A social accounting matrix model for Turkey
Yazar: YILMAZ GÜNEY
Danışman: PROF. DR. BEKİR KAYACAN
İstanbul Üniversitesi / Sosyal Bilimler Enstitüsü / İktisat Ana Bilim Dalı
Derece: Doktora, 2020
Konu: Ekonomi = Economics ; Maliye = Finance
Dizin: Ekonomik etki = Economic effect ; Gelir vergisi = Income tax ; Sosyal hesaplar matrisi = Social accounting matrix ; Vergi tarifesi = Tax schedules ; Vergiler = Taxes

Özet:
Türkiye'de gelir vergisi tarifesinin mükelleflerin en zaruri geçim koşulları için gereken gelir düzeylerinde bile yüksek oranlara sahip olması, başta gelir eşitsizliği ve vergi adaleti olmak üzere çok önemli toplumsal sorunlara neden olmaktadır. Bu sorunları çözmek için gereken politika adımlarının atılamadığı görülmüştür. Ayrıca, toplam vergi gelirleri içinde %22 gibi düşük bir paya sahip olan, resmi raporlara da yansıyan dar bir mükellef tabanı üzerinde yoğunlaşan Türk gelir vergisi sistemi, Onuncu Kalkınma Planı Vergi Özel İhtisas Komisyonu Raporunda da bahsedildiği üzere beklenilen verim düzeyinde değildir.
Söz konusu sorunların çözümüne bir katkı olması bakımından bu çalışmada 2012 yılı temel alınarak gelir vergisi sistemi incelenmiş, beyan ve gelir türlerine göre matrah ve vergi tutarları, biri daha ılımlı artan oranlı tarife diğeri ise düz oranlı tarife olmak üzere önerilen iki senaryoya göre hesaplama yapmaya uygun olacak şekilde sıklık dağılımları tahmin edilerek modellenmiştir. Her iki öneri mükellefler lehine daha az vergi ödemeyi gerektirdiğinden kullanılabilir gelirde ortaya çıkan farklar hesaplanarak makro ekonomik açıdan Sosyal Hesaplar Matrisi (SHM) tekniği ile analiz edilmiştir.
Çalışmada kullanılan SHM, 2012 yılı Girdi-Çıktı Tabloları ve Kurumsal Sektör Hesapları verileri esas alınarak gelir vergisi analizine uygun olabilecek bir tasarımla oluşturulmuştur. Daha sonra önerilen iki senaryodaki kullanılabilir gelir farklarının ekonomik etkileri dikkate alınarak her bir senaryo için ayrı birer SHM inşa edilmiştir. Bunu takiben elde edilen üç SHM üzerinden çarpan ve gelir etkisi analizleri yapılarak senaryoların uygulanabilirliği ile ortaya çıkan kamu finansman açığı sorgulanmıştır.
Neticede, senaryolardan herhangi birinin uygulanması halinde, Kalkınma Planlarındaki vergi adaletinin güçlendirilmesi, vergi tabanının genişletilmesi ve vergi hasılatının artırılması hedeflerine daha uygun bir gelir vergisi sistemi oluşabileceği, bu yapıların ek bazı önlemlerle kamu finansman dengesini önemli ölçüde etkilemeyeceği sonucuna varılmış, iyi tasarlanmış bir servet vergisiyle birlikte uygulanabilecek sabit oranlı tarifenin makro ekonomik açıdan daha isabetli olacağı önerilmiştir.

Anahtar Kelimeler: Gelir Vergisi Tarifesi, Artan Oranlı Tarife, Düz Oranlı Tarife, Sosyal Hesaplar Matrisi, Ekonomik Etki Analizi, Çarpan Analizi

Abstract:
The fact that income tax schedule of Turkey has a high level of taxation even for income levels that is necessary for taxpayers' most crucial means of living causes significant social issues such as income inequality and tax equity. Unfortunately, the essential steps in policy-making to solve this problem were previously not taken. Also, having a small share like 22% and intensification of tax on a limited taxpayers' base, as reflected in official reports like Tax Commission Report for 10th Development Plan, the Turkish income tax system is not at the expected efficiency level.
The aim of this study is to make contributions to solve this intricate problem. At first stage, it is determined that the tax brackets are narrower in width and the corresponding rates are higher in depth, especially at the lower income levels, as compared with some selected OECD countries' tax schedules. The comparison has been rendered through an index in which brackets are divided by annual minimum wage of each country.
The applied tax brackets for the year 2012 in Turkey stated as TL were (0- 10.000; 10.001-25.000; 25.001-58.000; 58.001 +) for none-wage earners and (0- 10.000; 10.001-25.000; 25.001-88.000; 88.001 +) for the wage earners; and the rates for both were (15%; 20%; 27%; 35%). The brackets have been proposed as (0-6.500; 6.501-25.000; 25.001-50.000; 50.001-75.000; 75.001-150.000; 150.001-300.000; 300.000 +) and the rates as (0%; 10%; 15%; 20%; 25%; 30%; 35%) for Scenario 1; the brackets as (0-6.500; 6.501 +) and the rates as (0%; %20) for Scenario 2. There is no income discrimination between wage and non-wage earners in both scenarios. In both scenarios, yearly tax credit which is estimated as TL 872,80 per wage earners is abolished; instead, zero tax rate is offered up to TL 6.500 income level for all, meaning a more advantageous tax amount for non-wage earners as TL 975 and for wage earners as TL 102,2 than the applied one.
Following that, the Turkish tax system has been examined selecting the year 2012 as the baseline. In addition, the frequency distribution of tax assessments and the amounts have been modeled using the tax returns data, so that they can be recalculated according to two proposed tax schedules: One is lightly progressive, and the other is flat-rate. Both proposals necessitate less tax payments for the benefit of taxpayers. The differences stemmed from the increase due to this factor in disposable income has been thus figured out, and the results has been analyzed by using Social Accounting Matrix (SAM) technique.
The theoretical base of SAM model is chosen from Pyatt and Round's Sri Lanka 1970 study and adapted to Turkish case: Production activities as the first of endogenous accounts of SAM have been selected from the Input-Output Tables of 2012 which includes 64 products and industries and grouped into six products and industries entitled as Agriculture, Production, Construction, Trade, Financial Services and Non-Financial Services, and then converted into industry-by-industry dimension using Model D which is known by its assumption of industry technology in the literature. Factors of Production as the second of endogenous accounts of SAM have been separated into two main categories as Labor and Other; Labor has been subdivided into three income groups entitled as Low 40%, Middle 40% and High 20% and Other has been separated into Capital and Other Taxes on Production. Households and Institutions as the third of endogenous accounts of SAM have been separated into two main categories as Households and Companies; Households have been subdivided into three income groups entitled as Low 40%, Middle 40% and High 20% ; and Companies have been separated into Financial Companies and Non-Financial Companies. Finally exogenous accounts have been examined under three categories such as Government, Consolidated Capital and Rest of the World (RW); Government has been subdivided into three groups entitled Government-Indirect Taxes, Government-Direct Taxes and Government-Current Accounts; Consolidated Capital has been kept by own name and Rest of the World has been separated into RW-Product Transactions and RW-Other accounts.
The SAM with above-mentioned headings has been constructed based on Input-Output Tables and Institutional Sector Accounts data for the year 2012 with a suitable design that can be used for income tax analysis. Alteration in an exogenous account like income tax that affects endogenous accounts through disposable income has to be carefully managed. In case of income tax differentiation, "the normalized expenditure coefficients would be altered, and the SAM and the matrix of full multipliers would have to be recalculated to reflect the change in direct taxes" as Holland and Wyeth pointed out.
Taking above explanations into consideration, two additional SAMs have been rebuilt for both proposed scenarios taking into account the economic impacts of disposable income increases for each one. The increased amount of disposable income has been distributed using the same expenditure schema for the first cycle. The demand shifts have been reflected to the production activities using matrix equations of the base model. Consequently, the new income distribution stemmed from production activities has been placed into the new matrices. The inequalities between rows and columns of the new matrices after these applications have been smoothed away under these assumptions: 1) Remaining disposable income from the first cycle for the households has been used for debt payments to Financial Corporations. 2) The remaining difference in Rest of the World-Production Transactions account in which imports are included, is eliminated with in the Government-Current Account as a saving. 3) The only remaining difference between the Government-Current Account and Financial Corporations has been fixed through the Government borrowing stemmed from final tax policy deficit which is lower than the first cycle.
TL 53,6 billion income tax for the base year is estimated as TL 37,3 billion for Scenario 1 and TL 43,9 billion for Scenario 2. After the first cycle, TL 16,2 billion deficit stemmed from Scenario 1 and TL 9,7 billion deficit stemmed from Scenario 2 at the beginning, has been placed to each SAM for Scenario 1 as TL 11,6 billion and TL 8,2 billion for Scenario 2 respectively.
Following that, the applicability of both scenarios and financial deficits of the Government have been questioned by analyzing multipliers and income effects based on three SAMs on hand. My findings regarding the Government deficits can be summarized as follows: 1) Even in the worst case, the yearly cost of Government borrowing has been calculated TL 1,2 billion for Scenario 1 and TL 0,8 billion for Scenario 2. These amounts can be neglected in the TL 317,1 billion total tax revenue when we consider social benefits of increasing disposable income. 2) In case of 5% increase in export, TL 6,1 billion Government revenue is expected for both scenarios according to leakage analysis of both SAMs. 3) Since Turkey has 27,2% informal economy which is well above the OECD countries' rate, a 5% reduction can be resulted in revenue increase such as TL 6,4 billion for Scenario 1 and TL 6,1 billion for Scenario 2. 4) In case of amendments in tax expenditure items, additional financing up to TL 3,6 billion could be expected.
Both estimated results for proposed scenarios are more suitable for the goals of Development Plans such as narrowing informal economy rather than increase in tax rates, reduction in tax expenditures, improvement in voluntary compliance to taxes, decreasing the tax burden on employment and enhancing tax credit application for every taxpayer.
Finally, it is concluded that income tax structure would not considerably affect the Government financial deficits in both proposed scenarios. From a macroeconomic point of view, it is proposed that flat-rate structure is more to the point when it is implemented with a well-designed property tax.

Key Words: Income Tax Structure, Progressive Tax System, Flat-rate Tax System, Social Accounting Matrix, Economic Impact Analysis, Multiplier Analysis.