The correlation between the dielectric constant and dispersion is investigated for barium strontium titanate (BST) capacitors with platinum and iridium electrodes. For platinum electrode capacitors, dispersion decreases with increasing dielectric constant. In contrast, capacitors with iridium electrodes exhibit the reverse correlation. A simple model is proposed to provide a quantitative explanation for the observed correlation for both platinum and iridium electrodes. In addition, the dependence of the dielectric constant and dispersion on varying ratios of (Ba+Sr)/Ti is also reported.