Abstract
This paper presented Kernel quantile regression in the prediction of inflation rate based on foreign exchange, crude oil price and currency in circulation. Two Radial basis kernel functions namely the Gaussian kernel and the Laplace kernel were applied in the analysis using four different sigma values (5,10,100,1000). Predictions at four quantiles (0.25, 0.50, 0.75 and 0.95) were made and comparison of the predicted values and the observed values were done based on the Root Mean Square Error of Prediction, Relative absolute error, Correlation and Paired T-test. Non-linearity test, normality test, Heteroscedasticity tests were carried out and the results revealed non-linearity, non-normality and presence of heteroscedasticity. The results reveal that the prediction error using the Gaussian kernel function was high for sigma 5,10,100, while that of the Laplace was only high for sigma value 5. The correlation between the observed and predicted was very high for both kernel functions at all quantiles but the paired t-test for the Gaussian kernel showed significant difference all the sigma except 1000, while there was not significant difference using the Laplace kernel at all quantiles. This paper concludes that the Laplace kernel is less sensitive to the sigma value as it makes good predictions at almost the whole considered sigma values but the Gaussian kernel is seen to have good prediction for sigma value 1000 hence it is very sensitive to the sigma value in the kernel function.