5. Empirical results5.1. OLS estimationTable 3 reports the results of the OLS estimation. The variables of market risk are positive and statistically significant for all individual bank stock and portfolio returns. Moreover, the results show that the market return explains a greater proportion of bank returns, compared to interest rate and FX rate returns. Evidence of interest rate sensitivity is not strong since the coefficients of interest rate return are significant in only 5 out of 14 cases. Evidence of FX rate sensitivity is stronger compared to interest rate sensitivity, except for Denizbank and Vakýfbank. The coefficient of FX rate return is significant and negative in 7 out of the 14 cases. Overall, most of the impact on the individual bank and portfolio returns is associated with the overall market returns and the FX rate returns.The suitability of the regression estimates is examined with the ARCH test. If the squared residuals in Eq. (1) contain autocorrelation or heteroscedasticity, it is likely that the null hypothesis will be rejected. The last column of Table 3 reports the results of the ARCH test. Unsurprisingly, a residual serial correlation is present for all the banks and the portfolio level analysis. The presence of residual autocorrelation is a very serious failure of the OLS classical assumption because its presence implies that the OLS coefficients are not efficiently estimated and statistical inferences based on standard t and F-tests would not be reliable. Therefore, GARCH type models would appear to be more appropriate for estimating such data.
đang được dịch, vui lòng đợi..
