I know that when circularly polarized light passes through a linear polarizer, the resulting intensity is half the initial intensity. This is because we can decompose the components of $\mathbf{E}$ on the axis of the polarizer and the axis perpendicular to the polarizer, and on average the field on both axes will be equal.
Does the same effect occur with elliptical polarization? Can we say that $I=I_0/2$ after passage through a linear polarizer?