A NOTE ON THE TRIMMED MEAN MEASURE OF CORE INFLATION IN SOUTH AFRICA

This paper constructs and analyses the properties of a trimmed mean inflation rate for South Africa. Based on an analysis of the distributions of the consumer price index component price changes, a measure is constructed that provides an estimator of core inflation, which may be particularly useful to policymakers in an inflation‐targeting environment. The trimmed mean estimator focuses on the price movements of individual components that have a strong bearing on the current and future trend of the headline inflation rate, allowing monetary policy to be directed at the persistent or underlying sources of inflationary pressures.     

A STOCHASTIC ESTIMATION FRAMEWORK FOR COMPONENTS OF THE SOUTH AFRICAN CONSUMER PRICE INDEX

Under inflation targeting in South Africa, it is important to monitor and forecast changes in prices, not only for aggregate measures of the consumer price index, but also its underlying sub-components. Hypotheses about sectoral transmission of policy and shocks are often more specific than hypotheses about overall transmission. This study employs a stochastic framework to estimate richly specified equilibrium correction models, four-quarters-ahead, for the 10 sub-components of the first targeted measure of the consumer price index, CPIX. The stochastic trends are estimated by the Kalman filter, and interpreted as capturing structural breaks and institutional change, a frequent cause of forecast failure. The trends suggest the design of deterministic split trends for use in recursive forecasting models, towards more accurate overall inflation forecasting. This research also has practical use for monetary policy in allowing identification of sectoral sources of inflation.     

INFLATION PERSISTENCE AND CORE INFLATION: THE CASE OF SOUTH AFRICA

This paper analyses the persistence of inflation in South Africa since 1981. A measure of the persistence of inflation provides important information about the impact of shocks on the economy over time. This information can be extremely useful for the purpose of setting monetary policy, especially in a small, open economy like South Africa. In addition, an estimate of persistence at the disaggregate level helps in the identification of the main drivers of aggregate inflation. This information is useful in deriving a core measure of South African inflation, which outperforms some of the more readily available core measures in identifying the underlying inflationary pressures in the economy.     

Price‐Setting Behaviour in Lesotho: Stylised Facts from Consumer Retail Prices

This paper documents some of the main features of price‐setting behaviour by retail outlets in Lesotho over the period March 2002 to December 2009. These features include the frequency, size, duration and synchronisation of price changes. In addition, the paper compares price‐setting behaviour in Lesotho and South Africa using a comparable set of products. The findings reveal considerable heterogeneity in price‐setting behaviour across products, outlets, locations and time. Variations in inflation are strongly correlated with the average size of price changes, but rising inflation raises the frequency of price increases and reduces the frequency of price decreases. Price decreases constitute an important determinant of inflation movements. Surprisingly, the frequency and size of price changes in Lesotho differ substantially from those in South Africa, despite the presence of common retail chains and their joint membership in a customs union and common monetary area. These findings open up opportunities for further research into the sources of heterogeneity across products and Lesotho and South Africa in the setting of prices.     

Towards a Measure of Core Inflation using Singular Spectrum Analysis

This paper constructs a number of possible core measures of inflation using singular spectrum analysis (SSA). Annual changes in monthly inflation are decomposed into its trend, oscillatory and noise components in order to develop an understanding of the trend and cyclicality in South African headline inflation. Three cyclical components with differing amplitude and frequency are identified. The trend and cyclical components of inflation are found to be a good approximation of core inflation, the inertial part of inflation. These core measures are compared with other candidate core measures based on the properties of a good core inflation measure. Generally, the SSA measures outperform commonly used measures of core inflation based on both in‐ and out‐of‐sample performance.     

FOOD INFLATION IN SOUTH AFRICA: SOME IMPLICATIONS FOR ECONOMIC POLICY

This paper analyses the trends in food price movements in South Africa between 1980 and 2008. There are three main results emanating from the analysis in this paper. Firstly, food price movements have played a large role in generating inflationary episodes in South Africa. Secondly, while external influences do matter, South African food price movements are mainly due to domestic influences. This implies that national policy has an important role to play in taming domestic food price inflation. Thirdly, given the strong second round impacts, food price movements warrant special attention in monetary policymaking. Core measures of inflation that exclude food price movements may not accurately reflect the underlying inflationary pressures in the economy and could compromise the attainment of the goal of price stability.     

THE SOUTH AFRICAN PHILLIPS CURVE: HOW APPLICABLE IS THE GORDON MODEL?

Is there a Phillips curve relationship present in South Africa and if so, what form does it take? Traditionally the method to establish whether or not there is a relationship between the output gap and the change in inflation is merely to regress the latter on the former. This yields the well‐known augmented Phillips curve. However, Gordon has argued that this specification of the Phillips curve produces biased results. Instead, he puts forward and estimates successfully for several industrialised countries his so‐called triangular model that tests for hysteresis and inertia in the behaviour of inflation, as well as the impact on inflation of changes in the output level. This paper considers whether or not Gordon's triangle model is applicable to South Africa, i.e. are hysteresis and inertia present in South Africa? In addition, in an attempt to find a better estimation of the output gap, the paper also experiments with alternative ways to estimate the long‐run output level, including the standard HP‐filter, as well as a production function approach.     

MEASURING THE WELFARE COST OF INFLATION IN SOUTH AFRICA

In this paper, we estimate the long‐run equilibrium relationship between money balance as a ratio of income and the Treasury bill rate for the period of 1965:02 to 2007:01, and in turn use the relationship to obtain welfare cost estimates of inflation. Using the Johansen technique, we estimate a log‐log specification and a semi‐log model of the above relationship. Based on the fits of the specifications, we decided to rely more on the welfare cost measure obtained under the log‐log money demand model. Our estimates suggest that the welfare cost of inflation for South Africa ranges between 0.34% and 0.67% of GDP, for a band of 3‐6% of inflation. Thus, it seems that the South African Reserve Bank's current inflation target band of 3‐6% is not too poorly designed in terms of welfare.     

A Note on the (Continued) Ability of the Yield Curve to Forecast Economic Downturns in South Africa

In 2002‐2003, the South African yield spread falsely signalled a downswing that never materialised. This paper provides two reasons for this false signal. First, while the Reserve Bank never actually officially declared the start of a downswing, by alternative measures a downswing did actually occur. It is this severe weakness in economic activity at that time that the yield curve pointed to. Second, short‐term interest rates in 2003 were higher than they should have been because of a mistake made in measuring consumer price inflation. Because South Africa had recently introduced an inflation‐targeting regime, policy interest rates were, as a result of this error, kept too high for too long. This policy mistake was rectified as soon as the error in the Consumer Price Index was discovered. Thus, the yield curve in 2003 pointed to the reality that short‐term interest rates were too high and risked pushing the economy into full blown recession. This is demonstrated by the fact that it was a fall in long bond interest rates that caused the yield spread to turn negative, indicating expectations that short‐term interest rates would need to be cut – as indeed they were.     

Revisiting the Exchange Rate Pass‐Through to Inflation in Africa’s Two Largest Economies: Nigeria and South Africa

This paper revisits the exchange rate pass‐through (ERPT) to inflation in Nigeria and South Africa by incorporating structural breaks and using time series variables, namely the consumer price index, nominal effective exchange rate, gross domestic product, and crude oil price. Based on the Maki cointegration test and a flexible estimation approach of the Autoregressive Distributed Lag (ARDL) model, our empirical evidence suggests that the long‐ and short‐run ERPT to inflation is complete for Nigeria, while for South Africa it is incomplete both in the long run and short run. This result indicates that prices are stickier in South Africa compared to Nigeria. The comparison between Nigeria and South Africa confirms the role of inflation targeting and central bank credibility on the ERPT. The results divulge further that output growth in Nigeria increases inflation in the long run while it is anti‐inflationary in the short run. For South Africa, the effect of output growth is negatively insignificant. In addition, the long‐run effect of oil price is negative and significant for Nigeria, while for South Africa the short‐run effect of oil price is positive and significant. Therefore, the findings of this paper will assist the monetary authorities to achieve monetary policy objectives.     

INFLATION TARGETING AND THE FISHER EFFECT IN SOUTH AFRICA: AN EMPIRICAL INVESTIGATION

The paper analyses the relationship between expected inflation and nominal interest rates during a period of inflation targeting in South Africa, i.e. from 2000 to 2005. Specifically, it investigates the Fisher hypothesis that nominal interest rates move one‐to‐one with expected inflation, leaving the real interest rate unaffected. The analysis distinguishes between a short‐run Fisher effect and a long‐run Fisher effect. Using cointegration and error correction models (for monthly data for the period April 2000 to July 2005), it was found that the short‐run Fisher hypothesis did not hold during the relevant period under the inflation targeting monetary policy framework in South Africa. This is attributed to a combination of the South African Reserve Bank's (SARB) control over short‐term interest rates and the effects of the monetary transmission mechanism. The long‐run Fisher hypothesis could not be confirmed in its strictest form: while changes in inflation expectations move in the same direction as the nominal long‐term interest rate. This suggests that monetary policy has an influence on the real long‐term interest rate, which has positive implications for general economic activity, thus confirming the credibility of the inflation targeting framework.     

Inflation in South Africa: An Assessment of Alternative Inflation Models

We consider the relative empirical performance of a range of inflation models for South Africa. Model coverage is of Phillips curve, New Keynesian Phillips curve, monetarist and structural models of inflation. Our core findings are that the single most robust covariate of inflation is unit labour cost. We further decompose unit labour cost into changes in the nominal wage and real labour productivity. The principal association is a strong positive relationship between inflation and nominal wages, while improvements in real labour productivity report only a relatively weak negative association with inflation. Supply‐side shocks also consistently report an association with inflation. As to demand‐side shocks, the output gap does not return a robust statistical association with inflation. Instead, it is growth in the money supply and government expenditure which return robust and theoretically consistent associations with inflationary pressure.     

ISOLATING A MEASURE OF INFLATION EXPECTATIONS FOR THE SOUTH AFRICAN FINANCIAL MARKET USING FORWARD INTEREST RATES

The inflation expectations channel of the transmission mechanism is generally recognised as crucial for the implementation of modern monetary policy. This paper briefly reviews the practices commonly employed for measuring inflation expectations in South Africa, and offers an additional method, which is market based. The methodologies of Nelson and Siegel and Svensson are applied to determine implied nominal and real forward interest rates. The difference between the nominal and real forward rates (called inflation compensation) on a particular day is then used as a proxy for the market's inflation expectations. This measure should not be viewed as a substitute for other measures of inflation expectations, but should rather supplement these in order to offer an additional insight.     

ON INFLATION

There is currently much more common sense in the South African inflation debate than a few decades ago. In particular, the South African Reserve Bank exhibits a pragmatic, eclectic approach to inflation (as reflected in its bi‐annual Monetary Policy Reports). This is in stark contrast to the narrow, monetarist‐type thinking that tended to dominate during the 1980s. This paper is an attempt to contribute to the debate by highlighting a few issues, including the widespread substitution of the CPI by the CPIX, the fact that inflation is a process, the need to combat inflation, the causes of the decline in inflation in South Africa and the essential features of an inflation‐targeting framework for monetary policy.     

FORECASTING SOUTH AFRICAN INFLATION

This paper looks at what variables are useful for forecasting inflation starting in 1990. I show that the output gap, a measure of real economic conditions, does seem to provide useful information for forecasting inflation. This is good news for the Reserve Bank, since the primary way that the Reserve Bank tries to affect future inflation is through real economic conditions. In addition, short‐term interest rates and import price inflation also seem to provide useful information. The most accurate of these forecasts suggests a root mean square forecast error of 1–2 per cent for 1‐year ahead inflation, which is within the Reserve Bank's current target range.     

MEASURING INFLATION CREDIBILITY: RESULTS OF A FIRST REPRESENTATIVE SOUTH AFRICAN SAMPLE

This study reports the measurement of inflation credibility of a representative sample of the South African population in terms of an inflation credibility barometer. The barometer is an instrument measuring the degree of acceptance of the accuracy of historic inflation figures. These research results serve as a benchmark for South Africa, as similar measurement of a representative sample has not been undertaken before. The sampling results show little public understanding of the rate of inflation and its measurement of average price increases experienced by an average household. As generally accepted international benchmarks for successful central-bank communication strategies do not exist, the application of the methodology reported in this paper can improve the effectiveness of central bank communication aimed at improving the general knowledge about inflation.     

THE SENSITIVITY OF SOUTH AFRICAN INFLATION EXPECTATIONS TO SURPRISES

Price stability is widely recognised as the primary goal of modern monetary policy, and the management of private sector inflation expectations has become an essential channel through which this goal is achieved. This evaluation aims to improve the understanding of how the sensitivity of private sector inflation expectations to macroeconomic surprises in South Africa compares internationally, as this provides an indication of the contribution of monetary policy in South Africa to anchoring inflation expectations. If a central bank is credible, the financial markets should react less sensitively to macroeconomics surprises, because they trust the central bank to manage these incidents and achieve the objectives they communicated over the medium to long term. In this paper, the methodology of Gurkaynack et al. is adopted in order to measure the sensitivity of South African inflation expectations to surprises. A comparison of South Africa's results with those of countries in the original studies supports the contention that the SARB (South African Reserve Bank) has encouraged inflation expectations to be relatively insensitive to macroeconomic surprises, and offers support for the inflation-targeting framework as a means to help anchor inflation expectations.     

Reactions to Shocks and Monetary Policy Regimes: Inflation Targeting Versus Flexible Currency Board in Sub‐Saharan Africa

The paper examines the monetary policy actions through which central banks in sub‐Saharan Africa have tried to eliminate the negative impacts of the shocks facing their economies. We compare two different monetary policy regimes: a currency board regime (in the CFA zone) and an inflation targeting policy regime (Ghana and South Africa) when central banks respond to demand, supply, and fiscal shocks. We extend the usual forecasting and policy analysis system models to replicate the economic features of these economies during the period 2002–12 and to evaluate the impact of several policies in response to these shocks. We find that both policies are inappropriate in helping the economies escape from the effects of negative demand shocks, both are essential when negative shocks to primary balance occur, while inflation targeting dominates the currency board regime as a strategy to cope with positive shocks to inflation.     

A Sticky Information Phillips Curve for South Africa

Mankiw and Reis propose the Sticky Information Phillips Curve (SIPC) as an alternative to the standard New Keynesian Phillips Curve to address empirical shortcomings in the latter. A SIPC for South Africa is estimated, and we find estimates of information updating probability between 0.69 and 0.81, somewhat higher than suggested by methods using micro‐evidence. Because the estimation requires data on expectations of current period inflation and output gap conditional on sequences of earlier period information sets, we provide a detailed analysis of the impact on our estimates of alternative proxies available in South Africa.     

INFLATION IN SOUTH AFRICA: A TIME‐SERIES VIEW ACROSS SECTORS USING LONG‐RANGE DEPENDENCE

In this paper I examine the time‐series evolution of the log consumer price index series in South Africa, disaggregating the data by sectors. I examine the time period 1990m1‐2008m12, i.e. focusing on the post‐apartheid period. I used methodologies based on fractional integration using parametric and semiparametric techniques. The results indicate that the (total) inflation rate in South Africa is long memory, with an order of integration in the range (0, 0.5). The same happens with most of the data disaggregated by sectors with values of d above 1 in the log prices. Evidence of I(0) inflation is obtained in some cases for “fruits and nuts”, “vegetables” and “sugar”, and evidence of mean reversion in the log prices is only obtained in the case of “fish and other seafood”.