  Recent measurements of the 2D Hall resistance show that the Hall coefficient
is independent of the applied in-plane magnetic field, i.e., the
spin-polarization of the system. We calculate the weak-field Hall coefficient
and the magnetoresistance of a spin polarized 2D system using the
semi-classical transport approach based on the screening theory. We solve the
coupled kinetic equations of the two carrier system including electron-electron
interaction. We find that the in-plane magnetic field dependence of the Hall
coefficient is suppressed by the weakening of screening and the
electron-electron interaction. However, the in-plane magnetoresistance is
mostly determined by the change of the screening of the system, and can
therefore be strongly field dependent.
