Longitudinal studies involving binary responses are widely applied in medical, health and economic science research, have focused increasingly on how various independent variables affect responses over time. These studies involve repeated observations on a subject and thus correlation within...

Banking sector which is the headstone of the financial sector in Turkey should profit. There are some indicators available to measure profitability of a bank and monitor the sustainability of the efficiency. These indicators are called financial ratios. In this study, 3-month dataset including...

The use of improved covariance matrix estimators as an alternative to the sample estimator is considered an important approach for enhancing portfolio optimization. Here we empirically compare the performance of nine improved covariance estimation procedures using daily returns of 90 highly...

For financial risk management it is of vital interest to have good estimates for the correlations between the stocks. It has been found that the correlations obtained from historical data are covered by a considerable amount of noise, which leads to a substantial error in the estimation of the...