External Reserves and the Policy Trilemma in Nigeria: Reassessing Monetary Policy Independence under Exchange Rate and Capital Flow Constraints

This study reassesses the role of external reserves in shaping Nigeria’s monetary policy independence within the framework of the policy trilemma, which highlights the inherent trade-offs among exchange rate stability, capital flow openness, and monetary autonomy. Using annual data from 1981 to 2023 and employing an Autoregressive Distributed Lag (ARDL) approach, the study explores how external reserves interact with exchange rate policies and capital mobility to influence Nigeria’s monetary autonomy. The study incorporates interaction effects to capture the conditional relationships between reserves and the other two legs of the trilemma. The model also incorporates key macroeconomic variables, including oil prices, inflation, financial development, and economic growth, to control for broader structural dynamics. Findings from the long-run analysis reveal that while external reserves are theoretically expected to enhance monetary policy independence, their effect is statistically insignificant, suggesting ineffective utilization. Exchange rate stability and capital mobility also show no significant long-run impact, indicating policy inconsistency and the limited effectiveness of Nigeria’s managed float regime and partial capital controls. Notably, oil price volatility emerges as the most significant determinant, with rising prices reducing the degree of monetary policy autonomy. Short-run dynamics reveal that reserves initially constrain policy independence but show a positive effect with lags, underscoring delayed policy transmission. Interaction terms between reserves and the trilemma components are also insignificant, suggesting that reserves have not functioned as a buffer against external constraints. Error correction estimates confirm that deviations from equilibrium are corrected rapidly, yet short-run dynamics reveal delayed and asymmetric policy effects. The findings underscore the need for a more coherent macroeconomic framework, improved reserve management, reduced oil dependency, and strengthened financial markets to enhance monetary policy independence in Nigeria.

Policy trilemma, external reserves, monetary policy independence

1. Adebiyi, M. A., Adeniyi, O. A., & Oyinlola, M. A. (2020). External reserves and policy trilemma in Nigeria. Journal of Economic Studies, 47(4), 833-846. [Google Scholar] [Crossref]

2. Adeniyi, O. A., Oyinlola, A. O., & Adejumo, A. O. (2017). External reserves and fiscal policy in Nigeria. Journal of Economic Policy Analysis, 7(1), 1-14. [Google Scholar] [Crossref]

3. Adeniyi, O., Oyinlola, M. A., & Adejumo, A. V. (2017). External reserves and economic growth in Nigeria. Journal of Economic Studies, 44(3), 541-555. [Google Scholar] [Crossref]

4. Adeoye, B. (2018). Political instability and economic growth in Nigeria. Journal of Economic Studies, 45(3), 541-555. [Google Scholar] [Crossref]

5. Aizenman, J., & Ito, H. (2013). The trilemma hypothesis: implications for monetary policy. NBER Working Paper No. 19231. [Google Scholar] [Crossref]

6. Aizenman, J., & Ito, H. (2015). East Asia's foreign exchange reserves and monetary policy. Journal of International Money and Finance, 51, 271-291. [Google Scholar] [Crossref]

7. Aizenman, J., & Lee, J. (2007). International reserves: precautionary versus mercantilist views, theory and evidence. Open Economies Review, 18(4), 191-214. [Google Scholar] [Crossref]

8. Aizenman, J., & Lee, J. (2008). International reserves and monetary policy. Journal of International Money and Finance, 27(8), 1276-1292. [Google Scholar] [Crossref]

9. Aizenman, J., & Marion, N. (2003). The high demand for international reserves in the Far East. Journal of International Money and Finance, 22(6), 761-779. [Google Scholar] [Crossref]

10. Aizenman, J., & Marion, N. (2003). The high demand for international reserves in the Far East: What is going on? Journal of the Japanese and International Economies, 17(3), 370-400. [Google Scholar] [Crossref]

11. Akinlo, A. E., Adejumo, A. O., & Olowookere, J. K. (2015). External reserves and monetary policy in Nigeria. Journal of Economic Studies, 42(5), 839-853. [Google Scholar] [Crossref]

12. Akinyemi, O., Egwaikhide, F. O., & Oyinlola, M. A. (2022). External reserves, exchange rates and capital flows in Africa. Journal of African Development, 24(1), 1-20. [Google Scholar] [Crossref]

13. Blanchard, O. J., & Kiyotaki, N. (1987). Monopolistic competition and the effects of aggregate demand. American Economic Review, 77(4), 647-666. [Google Scholar] [Crossref]

14. Calvo, G. A., Izquierdo, A., & Mejía, L. F. (2012). Systemic sudden stops: the relevance of balance-sheet effects and financial integration. Journal of International Economics, 88(2), 356-371. [Google Scholar] [Crossref]

15. CBN (2020). Annual Report and Statement of Accounts. [Google Scholar] [Crossref]

16. Chang, R. (2000). On the potential for self-fulfilling financial crises. Journal of Economic Theory, 94(2), 223-244. [Google Scholar] [Crossref]

17. Dominguez, K. M., Hashimoto, Y., & Ito, T. (2018). International reserves and global stability. Journal of International Economics, 110, 79-94. [Google Scholar] [Crossref]

18. Egwaikhide, F. O., Akinyemi, O., & Oyinlola, M. A. (2018). External reserves and economic growth in Nigeria. Journal of African Business, 19(2), 157-172. [Google Scholar] [Crossref]

19. Evans, G. W., & Honkapohja, S. (2001). Learning and expectations in macroeconomics. Princeton University Press. [Google Scholar] [Crossref]

20. Fleming, J. M. (1962). Domestic financial policies under fixed and under floating exchange rates. IMF Staff Papers, 9(3), 369-379. [Google Scholar] [Crossref]

21. Fleming, M. (1962). Domestic financial policies under fixed and under floating exchange rates. IMF Staff Papers, 9(3), 369-379. [Google Scholar] [Crossref]

22. Flood, R. P., & Marion, N. P. (2002). Holding international reserves in an era of high capital mobility. Journal of Economic Integration, 17(2), 257-274. [Google Scholar] [Crossref]

23. Gali, J., & Monacelli, T. (2005). Monetary policy and exchange rate volatility in a small open economy. Review of Economic Studies, 72(3), 707-734. [Google Scholar] [Crossref]

24. Ghosh, A. R., Ostry, J. D., & Chamon, M. (2017). Exchange rate management and monetary policy in emerging markets. Journal of Development Economics, 125, 333-345. [Google Scholar] [Crossref]

25. Ghosh, A. R., Ostry, J. D., & Tsangarides, C. (2012). International reserve accumulation and monetary policy. Journal of International Economics, 88(2), 336-345. [Google Scholar] [Crossref]

26. Ikoh, Itoro Moses (2019) Fiscal Policies and Standard of Living in Nigeria: Investigating the Trend 1998 – 2016. Fulafia Journal of Social Sciences 2(1):25-43 [Google Scholar] [Crossref]

27. IMF (2012). The liberalization and management of capital flows: an institutional view. IMF Staff Position Note, SPN/12/10. [Google Scholar] [Crossref]

28. Iyoha, M. A. (2013). Dutch disease and the Nigerian economy. Journal of Economic Policy Studies, 10(1), 1-18. [Google Scholar] [Crossref]

29. Jeanne, O., & Rancière, R. (2011). The optimal level of international reserves for emerging market countries: A new formula and some applications. Economic Journal, 121(555), 905-930. [Google Scholar] [Crossref]

30. Krugman, P. (1999). Balance Sheets, the Transfer Problem, and Financial Crises. International Tax and Public Finance, 6(4), 459-472. [Google Scholar] [Crossref]

31. Krugman, P. (2012). International trade and finance. In P. Krugman and M. Obstfeld (Eds.), International Economics (9th ed., pp. 537-566). [Google Scholar] [Crossref]

32. Krugman, P. (2012). International trade and finance. In P. Krugman and M. Obstfeld (Eds.), International Economics (9th ed., pp. 537-566). [Google Scholar] [Crossref]

33. Lane, P. R. (2001). The new open economy macroeconomics: a survey. Journal of International Economics, 54(2), 235-266. [Google Scholar] [Crossref]

34. Lane, P. R., & Milesi-Ferretti, G. M. (2007). The external wealth of nations marked II. Journal of International Economics, 73(2), 223-250. [Google Scholar] [Crossref]

35. Lane, P. R., & Milesi-Ferretti, G. M. (2007). The external wealth of nations mark II: Revised and extended estimates of foreign assets and liabilities, 1970-2004. Journal of International Economics, 73(2), 223-250. [Google Scholar] [Crossref]

36. Mohanty, M. S., & Turner, P. (2006). Foreign exchange reserve accumulation in emerging markets. BIS Quarterly Review. [Google Scholar] [Crossref]

37. Mohanty, M. S., & Turner, P. (2006). Foreign exchange reserve accumulation in emerging markets. BIS Quarterly Review, March 2006, 39-51. [Google Scholar] [Crossref]

38. Mundell, R. A. (1963). Capital mobility and stabilization policy under fixed and flexible exchange rates. Canadian Journal of Economics, 29(4), 475-485. [Google Scholar] [Crossref]

39. Mundell, R. A. (1963). Capital mobility and stabilization policy under fixed and flexible exchange rates. Canadian Journal of Economics, 29(4), 475-485. [Google Scholar] [Crossref]

40. Mundell, R. A. (1963). Capital mobility and stabilization policy under fixed and flexible exchange rates. Canadian Journal of Economics, 29(4), 475-485. [Google Scholar] [Crossref]

41. NBS (2020). Labour Force Statistics. [Google Scholar] [Crossref]

42. Nwosa, P. I., Oaikhenan, H. E., & Okoroafor, O. C. (2019). External reserves and exchange rate volatility in emerging markets. Journal of International Financial Markets, Institutions and Money, 59, 241-253. [Google Scholar] [Crossref]

43. Obstfeld, M. (2014). The international monetary system: a bird’s-eye view. Journal of Economic Perspectives, 28(1), 147-166. [Google Scholar] [Crossref]

44. Obstfeld, M. (2015). Trilemmas and trade-Offs: living with globalization. Federal Reserve Bank of San Francisco Working Paper Series. [Google Scholar] [Crossref]

45. Obstfeld, M., & Rogoff, K. (1995). Exchange rate dynamics redux. Journal of Political Economy, 103(3), 624-660. [Google Scholar] [Crossref]

46. Obstfeld, M., Shambaugh, J. C., & Taylor, A. M. (2009). Financial instability, reserves, and central bank swap lines in the panic of 2008. American Economic Review, 99(2), 481-486. [Google Scholar] [Crossref]

47. Obstfeld, M., Shambaugh, J. C., & Taylor, A. M. (2010). Financial stability, the trilemma, and international reserves. American Economic Journal, 2(2), 57-94. [Google Scholar] [Crossref]

48. Obstfeld, M., Shambaugh, J. C., & Taylor, A. M. (2010). Financial stability, the trilemma, and international reserves. American Economic Journal: Macroeconomics, 2(2), 57-94. [Google Scholar] [Crossref]

49. Obstfeld, M., Shambaugh, J. C., & Taylor, A. M. (2019). Global capital markets and the transmission of financial shocks. Journal of Financial Economics, 133(3), 537-553. [Google Scholar] [Crossref]

50. Olabisi, M. O. (2017). Policy trilemma and economic stability in Nigeria. Journal of Economic Theory, 11(2), 123-140. [Google Scholar] [Crossref]

51. Olowookere, J. K., Adebiyi, M. A., & Ogunmuyiwa, M. S. (2023). External reserves and policy trilemma constraints in emerging markets. Journal of International Money and Finance, 131, 102654. [Google Scholar] [Crossref]

52. Oshikoya, T. (2015). Nigeria's trilemma: exchange rate, interest rate, and capital controls. African Development Bank Working Paper Series, No. 221. [Google Scholar] [Crossref]

53. Oshikoya, T. (2016). The evolution of the trilemma Indices in Nigeria: 1960-2014. Presented at the African Economic History Workshop, University of Oxford. [Google Scholar] [Crossref]

54. Ostry, J. D., Ghosh, A. R., & Chamon, M. (2012). Two targets, two instruments: monetary and exchange rate policies in emerging market economies. IMF Staff Papers, 59(2). [Google Scholar] [Crossref]

55. Ostry, J. D., Ghosh, A. R., & Chamon, M. (2016). Two targets, one instrument: Monetary policy in emerging market economies. Journal of International Money and Finance, 60, 157-176. [Google Scholar] [Crossref]

56. Ozoh, G. I., Ejem, A. O., & Onwuka, K. O. (2016). External reserves, exchange rates and capital flows in Nigeria. International Journal of Economics and Financial Issues, 6(4), 153-160. [Google Scholar] [Crossref]

57. Park, J., & Estrada, G. (2014). International reserve accumulation and exchange rate dynamics. Journal of International Money and Finance, 49, 327-343. [Google Scholar] [Crossref]

58. Puckelwald, A. (2012). The trilemma of financial globalization: how to balance financial stability, monetary policy independence, and capital mobility. Journal of Economic Issues, 46(3), 675-691. [Google Scholar] [Crossref]

59. Rodrik, D. (2006). The social cost of foreign exchange reserves. International Journal of Political Economy, 36(3), 3-13. [Google Scholar] [Crossref]

60. Smets, F., & Wouters, R. (2003). An estimated dynamic stochastic general equilibrium model of the euro area. Journal of the European Economic Association, 1(5), 1123-1175. [Google Scholar] [Crossref]

61. Taylor, J. B. (2000). Low inflation, pass-through, and the pricing power of firms. European Economic Review, 44(7), 1389-1408. [Google Scholar] [Crossref]

62. World Bank (2020). World Development Indicators [Google Scholar] [Crossref]

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