Assessing alternative monetary policy frameworks and instruments in selected African economies
Chiumia, Austin Belewa
This thesis contains three core chapters that assess the performance of alternative monetary policy frameworks and instruments in stabilizing 10 selected African economies. Literature and practice show that Advanced Economies (AEs) and Emerging Market Economies (EMEs) are mostly adopting the ination targeting (IT) framework. This framework relies on active use of the interest rate as a policy instrument for macroeconomic stabilisation. Di⁄erent from AEs and EMEs, the majority of African countries are characterized by low nancial market development, frequent supply shocks and volatile terms of trade. These features impede the e¢ ciency of the IT framework and the interest rate instrument. Supply shocks imply that ination is not only demand driven. Volatile terms of trade translate into excessive exchange rate uctuations. Due to these factors, policy practice in Africa remains largely divergent from the global trend. Authorities still rely on monetary aggregate targeting (MAT) with de facto managed exchange rates. However, the MAT framework is also failing to stabilize economies. This follows instability of the key factors, such as the money demand, upon which the framework is anchored. Furthermore, controlling exchange rate movements is a challenge due to weak balance of payments positions. It is not surprising, therefore, that the majority of African economies still remain in the grip of macroeconomic instability. Ination and GDP targets are rarely met and they also remain volatile. The perverse macroeconomic features and the perceived failure of the MAT regime have necessitated the search for alternative monetary frameworks and instruments. In this study, we join the search by specically focussing on three questions. First, given the macroeconomic landscape in Africa, what is the relative performance of the interest rate vis--vis the monetary aggregate as instru iv ments for macroeconomic stabilization? Secondly, how do these instruments perform when apart from ination and output stabilization, monetary policy also engages in smoothing exchange rate uctuations? Thirdly, what is the relative performance of ination targeting vis--vis nominal GDP targeting as alternative monetary policy regimes for macroeconomic stabilization in African economies? Although the success of monetary policy largely relies on appropriate conguration of monetary policy frameworks and instruments, answers to these questions remain controversial and scanty for African economies. In order to address these questions, we formulate a New Keynesian Dynamic Stochastic General Equilibrium (DSGE) model. In this model, money is non-separable from consumption in the utility function. We estimate the model using the Maximum Likelihood method with quarterly data mostly from 1990 to 2014. The data is obtained from the International Financial Statistics (IFS). The thesis has ve chapters. Chapter 1 is the general background to the research problem. Chapters 2, 3 and 4 are distinct but related core chapters addressing three specic research questions. Chapter 5 is the conclusion. In Chapter 2, we compare the performance of the monetary aggregate and the interest rate as alternative instruments for stabilizing ination and output in 10 selected countries. Results show that the monetary aggregate is superior in stabilizing 5 economies. In the other 5 countries, it is the interest rate instrument which performs better. In the former group of countries, the monetary aggregate plays a relatively large role in macroeconomic dynamics while in the latter the interest rate is more signicant. These results partly reect di⁄erences in nancial market development between the two groups of countries. Overall, we nd a weak role of the interest rate compared to the monetary aggregate in driving aggregate demand dynamics. The exchange rate is also found to be a key driver of macroeconomic dynamics. Our re v sults suggest three things: First, authorities in Africa need to be cautious of a blanket adoption of the interest rate as a sole monetary policy instrument. Second, authorities will nd it di¢ cult to stabilize economies using the interest rate based frameworks. Third, exchange rate stability is key to macroeconomic stability in Africa. In Chapter 3, we extend the authoritiesobjective function. In addition to minimizing ination and output volatility, authorities also use the interest rate or money supply rules to smooth exchange rate uctuations. The results show that macroeconomic performance is enhanced when authorities smooth exchange rate uctuations in 4 of the 10 countries. The gains from exchange rate smoothing mostly arise from a reduction in ination and exchange rate volatility but not fromoutput. In the other 6 countries, exchange rate smoothing worsens macroeconomic performance. These results reect the fact that the exchange rate exerts a relatively large inuence in macroeconomic dynamics in the rst group of countries compared to the latter. Exchange rate smoothing therefore minimizes the pass-through of the exchange uctuations to ination and output leading to better performance. Overall, the ndings suggest that exchange rate smoothing is harmful in Africa. Where exchange rate smoothing delivers gains, appropriate thresholdsofsmoothingneedtobeobservedtoavoidpolicyinducedmacroeconomic instability. Authorities should also smooth temporal rather that structural shifts in the exchange rate level. In Chapter 4, we compare the performance of ination targeting (IT) vis-vis nominal GDP targeting (NGDPT) as alternative monetary policy frameworks for macroeconomic stabilization. We examine the strict and exible versions of these policy regimes. We also include a hybrid regime which combines elements of IT and NGDPT. Results show that the hybrid regime performs better in 5 countries. In the other 4 countries, it is the strict ination targeting that performs better. In 1 country, exible ination tar vi geting is optimal. The results also reveal that demand shocks dominate but are closely trailed by supply and exchange rate shocks in explaining macroeconomic uctuations. The multiplicity of signicant shocks is key in explaining the dominance of the hybrid regime. The hybrid regime successfully handles shocks that can neither be optimally handled by the IT regime nor the NGDPT regime alone. These results have several implications. First, demand management alone is insu¢ cient to stabilize African economies. Second, identifying dominant shocks is critical for choosing robust monetary policy regimes. Third, the multiplicity of signicant shocks implies that choosing monetary policy frameworks and hence macroeconomic management process is more complex for African policy makers. Overall, the results have several policy implications which are outlined in Chapter 5. First, they suggest a cautious approach towards generalized adoption of the interest rate over the monetary aggregate as a monetary policy instrument in African economies. This contradicts the current wave of monetary policy changes sweeping across African countries. Secondly, the signicanceoftheexchangeraterenderscredencetoexchangeratesmoothing in Africa. The ndings, however, suggest that exchange rate smoothing can either enhance or worsen macroeconomic performance. Where it enhances macroeconomic performance, authorities must carefully consider the thresholds of smoothing to avoid creating macroeconomic instability. Authorities need not ght structural shifts in exchange rates levels through smoothing. This would help to preserve the shock absorbing role of the exchange rate. Finally, the prevalence of demand, supply as well as exchange rate shocks makes the hybrid monetary policy regime which combines elements of IT regime as well as NGDPT regime to perform relatively better in stabilizing the majority of the economies. Given the multiplicity of shocks, authorities inAfricaneedtocomplementdemandmanagementwithpoliciesthataddress supply side and exchange rate bottlenecks to ensure sustainable macroeco vii nomic stability. Overall, the ndings suggest that there is scope to improve monetary policy performance in Africa by adopting suitable frameworks and instruments. The results also highlight the problem of tackling monetary policy issues with a "one size ts all" approach.
A thesis submitted to the Faculty of Commerce, Law and Management, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the Degree of Doctor of Philosophy in Economics, October, 2017
Chiumia, Austin Belewa (2017) Assessing alternative monetary policy frameworks and instruments in selected African economies, University of the Witwatersrand, Johannesburg, <https://hdl.handle.net/10539/24341>