TİCARET SAVAŞLARI VE PİYASA OYNAKLIĞI: GÜMRÜK VERGİSİ POLİTİKALARININ EGARCH MODELİ İLE ANALİZİ

Öz

Bu çalışma, Trump yönetiminin 2018 yılında başlattığı ilave gümrük vergilerinin ABD’nin dış ticaretinde ithalat oynaklığı üzerindeki etkisini incelemektedir. ABD’nin en önemli ticaret ortaklarından Meksika, Çin, Kanada ve Almanya’dan yapılan ithalat; otomotiv (87. Fasıl), demir-çelik (73. Fvolasıl) ve makine (84. Fasıl) sektörleri çerçevesinde değerlendirilmiştir. 2005-2024 dönemi aylık ithalat verileri kullanılarak serilerin birinci farkları alınmış ve volatilite analizleri için EGARCH modeli uygulanmıştır. Elde edilen bulgular, Trump yönetimi tarafından uygulanan tarifelerin özellikle Meksika ve Çin’den yapılan ithalat üzerinde oynaklık yaratıcı ve kalıcı etkiler bıraktığını göstermektedir. Kanada ve Almanya ile olan ticarette ise ithalat volatilitesinin görece daha istikrarlı seyrettiği tespit edilmiştir. Sektörel bazda, otomotiv ve makine ithalatında oynaklık şoklarının kalıcılığı daha yüksek bulunmuştur. Trump’ın 2025 yılında ikinci kez göreve gelmesi ve demir-çelik ile otomotiv sektörlerinde yeni tarifeleri uygulamaya koyması, özellikle Meksika ve Çin ile olan ithalat süreçlerinde yeni belirsizlikler yaratma potansiyeline sahiptir. Çalışma bulguları, gümrük tarifeleri gibi korumacı politikaların sadece ithalat hacmini azaltmakla kalmayıp, ticaretin sürdürülebilirliğini olumsuz etkileyerek piyasada uzun vadeli belirsizliklere yol açtığını ortaya koymaktadır.

Anahtar Kelimeler

• Trump Dönemi Tarifeleri
• Volatilite
• egarch model
• ithalat

TRADE WARS AND MARKET VOLATİLİTY: AN ANALYSİS OF TARİFF POLİCİES USİNG THE EGARCH MODEL

Öz

This study examines the impact of additional tariffs imposed by the Trump administration in 2018 on import volatility in the U.S. foreign trade. Imports from Mexico, China, Canada, and Germany, which are among the most significant trading partners of the U.S., have been analyzed within the framework of the automotive (Chapter 87), iron-steel (Chapter 73), and machinery (Chapter 84) sectors. Monthly import data for the period 2005-2024 have been used, and first differences of the series were taken, followed by the application of the EGARCH model for volatility analyses. The findings indicate that the tariffs implemented by the Trump administration had volatility-inducing and persistent effects, particularly on imports from Mexico and China. In contrast, imports from Canada and Germany exhibited relatively more stable volatility patterns. On a sectoral basis, the persistence of volatility shocks was found to be higher in automotive and machinery imports. Trump's potential re-election in 2025 and the introduction of new tariffs in the iron-steel and automotive sectors pose the risk of creating further uncertainties, especially in import processes with Mexico and China. The study's findings reveal that protectionist policies, such as tariffs, not only reduce import volumes but also negatively affect trade sustainability by causing long-term uncertainties in the market.

Anahtar Kelimeler

• Trumps admistiation tariff
• volatility
• egarch models
• import

Kaynakça

1. Amiti, M., Redding, S. J., & Weinstein, D. E. (2019). The impact of the 2018 tariffs on prices and welfare. Journal of Economic perspectives, 33(4), 187-210.
2. Baley, I., Veldkamp, L., & Waugh, M. (2020). Can global uncertainty promote international trade? Journal of International Economics, 126, 103347.
3. Bera, A. K., & Jarque, C. M. (1981). Efficient tests for normality, homoscedasticity and serial independence of regression residuals: Monte Carlo evidence. Economics Letters, 7(4), 313-318.
4. Bertil, O. (1933). Interregional and international trade. Cambrige: Harward University Press, 1933.–188 р.
5. Bollerslev, T. (1986). Generalized autoregressive conditional heteroskedasticity. Journal of econometrics, 31(3), 307-327.
6. Breusch, T. S. (1978). Testing for autocorrelation in dynamic linear models. Australian Economic Papers, 17(31).
7. Caldara, D., Iacoviello, M., Molligo, P., Prestipino, A., & Raffo, A. (2020). The economic effects of trade policy uncertainty. Journal of monetary economics, 109, 38-59.
8. Crowley, M., Meng, N., & Song, H. (2018). Tariff scares: Trade policy uncertainty and foreign market entry by Chinese firms. Journal of International Economics, 114, 96-115.

9. De Sousa, J., Disdier, A.-C., & Gaigné, C. (2020). Export decision under risk. European economic review, 121, 103342.
10. Dickey, D. A., & Fuller, W. A. (1979). Distribution of the estimators for autoregressive time series with a unit root. Journal of the American statistical association, 74(366a), 427-431.
11. Engle, R. F. (1982). Autoregressive conditional heteroscedasticity with estimates of the variance of United Kingdom inflation. Econometrica: Journal of the econometric society, 987-1007.
12. Engle, R. F. (1983). Estimates of the Variance of US Inflation Based upon the ARCH Model. Journal of money, credit and banking, 15(3), 286-301.
13. Esposito, F. (2018). Entrepreneurial risk and diversification through trade. Available at SSRN.
14. Fajgelbaum, P. D., Goldberg, P. K., Kennedy, P. J., & Khandelwal, A. K. (2020). The return to protectionism. The quarterly journal of economics, 135(1), 1-55.
15. Feng, L., Li, Z., & Swenson, D. L. (2017). Trade policy uncertainty and exports: Evidence from China's WTO accession. Journal of International Economics, 106, 20-36.
16. Giovanni, J. d., & Levchenko, A. A. (2009). Trade openness and volatility. The review of Economics and Statistics, 91(3), 558-585.
17. Godfrey, L. G. (1978). Testing for higher order serial correlation in regression equations when the regressors include lagged dependent variables. Econometrica: Journal of the econometric society, 1303-1310.
18. Handley, K. (2014). Exporting under trade policy uncertainty: Theory and evidence. Journal of International Economics, 94(1), 50-66.
19. Handley, K., & Limão, N. (2017). Policy uncertainty, trade, and welfare: Theory and evidence for China and the United States. American economic review, 107(9), 2731-2783.
20. Heckscher, E. F. (1919). The effect of foreign trade on the distribution of income.
21. Héricourt, J., & Nedoncelle, C. (2018). Multi-destination firms and the impact of exchange-rate risk on trade. Journal of Comparative Economics, 46(4), 1178-1193.
22. Irwin, D. A. (2017). Peddling protectionism: Smoot-Hawley and the great depression. Koren, M., & Tenreyro, S. (2007). Volatility and development. The quarterly journal of economics, 122(1), 243-287.
23. Lewis, L. T. (2014). Exports versus multinational production under nominal uncertainty. Journal of International Economics, 94(2), 371-386.
24. Nelson, D. B. (1991). Conditional heteroskedasticity in asset returns: A new approach. Econometrica: Journal of the econometric society, 347-370.
25. Nguyen, D. X. (2012). Demand uncertainty: Exporting delays and exporting failures. Journal of International Economics, 86(2), 336-344.
26. Ramondo, N., Rappoport, V., & Ruhl, K. J. (2013). The proximity-concentration tradeoff under uncertainty. Review of Economic Studies, 80(4), 1582-1621.
27. Yang, Z., & Hong, J. (2021). Trade policy uncertainty and energy intensity: evidence from Chinese industrial firms. Energy Economics, 103, 105606.