Title: Determining the threshold of the exchange rate instability for South Africa

Authors: Simiso Msomi; Paul-Francois Muzindutsi

Addresses: School of Accounting, Economics and Finance, University of KwaZulu Natal, Westville Campus, Durban 3629, South Africa ' School of Accounting, Economics and Finance, University of KwaZulu Natal, Westville Campus, Durban 3629, South Africa

Abstract: Despite extensive literature, understanding exchange rate dynamics remains a challenging subject in the macroeconomics literature. For instance, the South African rand against the USA dollar has constantly experienced depreciating exchange rates since the 1960s. In the early 2000s, a rapid exchange rate depreciation led to the formation of the Myburgh Commission to investigate the causes of the exchange rate depreciation. However, the commission failed to point out the causes of the unexpected movement of the exchange rate. This study uses the SETAR model to determine the threshold value at which the exchange rate movement can be considered as exhibiting unusual behaviour. Thus, if the exchange rate movement exceeds the particular threshold value, then it is associated with a higher risk of exchange rate instability. The study established that when the exchange rate depreciates by more than 1.905% points, there is a higher risk of instability for the rand. Furthermore, the study finds that the South African exchange rate is currently in an unstable state.

Keywords: exchange rates; instability; depreciation; appreciation; South Africa.

DOI: 10.1504/IJMEF.2025.148856

International Journal of Monetary Economics and Finance, 2025 Vol.18 No.5, pp.341 - 348

Received: 09 Feb 2024
Accepted: 30 Oct 2024

Published online: 29 Sep 2025 *

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