Optimal Short-Term Inflation Rate Forecasting Model in Kenya:
in Depth Analysis
1Philip Kilonzi, 2Dr. Richard siele, 3Dr. Elvis Kiano
1Lecturer Economics department, Multimedia university of Kenya.
2,3Senior Lecturer Economics department, Moi University Kenya.
https://doi.org/10.47191/jefms/v7-i9-11
ABSTRACT:
Purpose:
The Kenya economy experienced an increase in the price of basic commodities, increased unemployment rates and
consequently reduced real wage levels due to job cuts. An accurate forecast of this unprecedented inflation rate could have
cushioned the Kenyan population from its effects. Uncertainty over future inflation forecasting has caused detrimental and
negative impact not only globally but also in the Kenyan economy. Combining several techniques of forecasting is an instinctual
way to improve prediction performance as the limitations of one method are compensated by the strength of the other model.
The general objective of the study was to develop an optimal model of forecasting short term inflation rate in Kenya. The specific
objectives were to establish models of forecasting short term inflation rate using SARIMA, GARCH and hybrid SARIMA-GARCH
family Models, select optimal model amongst the three models and Predict 12 months ahead inflation rate using the optimal
model. Scope of the study from 2005 January to 2024 July. The study was anchored on monetary theory of inflation, Keynesian
theory of inflation as well as rationale expectation theory of inflation.
Methodology:
Data was sourced from KNBS and CBK. The study was guided by positivism research philosophy. Explanatory
research design was used in this study. Target population was 230 monthly observations. Sample and sampling techniques used
was time series. PACF, ACF Dfuller, Kpss test, Philips perron test indicated the data was stationary after 1ST differencing.
Findings:
Statistic validation test results indicated SARIMA’s (1,1,1)(1,1,)12 adjusted 2 R was perfectly 1 indicating all variations
in squared residuals were explained by lagged residuals. P- value for lagged squared residuals were significant at (0.00). F-statisticvalue
was significant (0.020) suggesting overall model fit. Model stability test AR roots polynomial lied outside the unit circle.
eGarch(1,1) model with lowest aic -0.534 was best in Garch Family models. Hybrid Sarima((1,1,1),(1,1,1) eGARCH(1,1) was
identified. Comparison of Sarima(1,1,1)(1,1,1)12, eGARCH (1,1) and Hybrid Sarima((1,1,1),(1,1,1)12 eGARCH(1,1) using forecast
accuracy revealed that hybrid model was the optimal model with lowest MAE 0.166 and RMSE 0.259. Diagnostic checks The Ljung-
Box test (LL) and Q2 indicated non-significant autocorrelation p- value were greater than 05% indicating that the models residuals
were white noise. The DOF/GED parameter (4.144466*, 1.101958, 6.977499) represented the degrees of freedom for the tdistribution
and the coefficients where significant at 0.05% meaning the model’s assumptions for normal distributions were met.
The coefficients of AR Normal 0.048140, T-Student −0.031854, GED −0.02396 and MA Normal 0.055167 ,T-Student 0.059645,
GED 0.051390 terms were significant at 5%.
Recommendations:
The results implied that the model predicted a decrease in the Kenya’s inflation rate for the next 12 months.
The study recommended that inflation rate would be hovering below an average rate of 10 within the next 12 months with high
volatility up to July 2025 and policy makers should use this prediction for planning in order to maintain Kenya’s macroeconomic
stability. Policy makers were also advised to use the hybrid model to forecast short term inflation rate 12 months ahead and in
future years. The benefits of the study were added knowledge of hybridizing to researchers and to policy makers. This study
therefore provided better inflation forecasts (Kenya) to be used for strategical planning for short -term effects of inflation by the
government.
KEYWORDS:
Inflation rate forecasting, Time series Forecasting, Sarima, Hybrid Sarima Garch family model.
REFERENCES:
1) Blanchard, Olivier (2000). Macroeconomics (2nd ed.). Englewood Cliffs, N.J: Prentice Hall.
2) Enke, D & Mehdiyev, N (2014). A Hybrid Neuro-Fuzzy Model to Forecast Inflation, Procedia Computer Science, 36 (2014): 254 – 260.
3) International Monetary Fund (2022). Tackling Rising Inflation in Sub-Saharan Africa. October 2022 Regional Economic Outlook: Sub-Saharan Africa Analytical Note.
4) Lin, T., Guo, T., and Aberer, K. (2017). Hybrid neural networks over time series for trend.
5) Fisher JD, Liu CT, Zhou R. When can we forecast inflation?. Economic Perspectives-Federal Reserve Bank of Chicago. 2002; 26(1): 32-44.
6) DK Dalling, DM Grant, EG Paul(1973) Carbon-13 magnetic resonance. XXIII. Methyldecalins Journal of the American Chemical Society, 1973•ACS Publications.\
7) Petrică, a. c., & Stancu, s. (2017). empirical results of modeling eur/ron exchange rate using arch, garch, egarch, tarch and parch models. romanian statistical review, (1).
8) Huang T, et al. (2012) Deciphering the effects of gene deletion on yeast longevity using network and machine learning approaches. Biochimie 94(4):1017-25.
9) E.M. Huseynov, AA Garibov, RN Mehdiyeva Fizika (Baku), (2014) Influence of neutron irradiation on the temperature dependence of permittivity of NaNoSiO {sub 2}; Neytron selinin NaNoSiO {sub 2}-nin dielektrik xasselerinin.
10) Central Bank of Kenya(2017). Bank Supervision Annual Report 2017.
11) J. Callejo Gallego - Revista española de salud pública, (2002) - SciELO Public Health Antes de entrar en la oposición entre perspectiva cuantitativa y perspectiva cualitativa de la investigación social, se argumenta la necesidad de considerar el proceso de investigación.
12) Kiptui, M. C. (2013). The P-Star Model of Inflation and Its Performance for the Kenyan. Economy. International Journal of Economics & Finance, 5(9).
13) S. Selvi, M. Chandrasekaran(2018). Framework to forecast environment changes by optimized predictive modelling based on rough set and Elman neural network. Soft Computing 24 (14), 10467-1048.
14) Hyndman, R. J., Koehler, A. B., Ord, J. K. and Snyder, R. D. (2005) Prediction intervals for exponential smoothing state space models. Journal of Forecasting, 24, 17-37.