  We show that the Hall coefficient of the boson+fermion dimer model for the
pseudogap phase of high temperature superconductivity introduced in Punk et al.
changes sign from negative at low temperatures to positive at high temperatures
at a characteristic temperature scaling proportional to the the cyclotron
frequency of the fermionic dimers (divided by k), (here k~0.7 fits the
experimental data well). We show that this is an effect of the changing of the
sign of the coupling between the fermionic dimer and the magnetic field from
negative coupling -e at low temperatures to positive coupling +e at high
temperature, with the Hall coefficient being proportional to R_H~e_B*e_E*e_J
(the product of the magnetic charge, electric charge and current charge all of
which we carefully define). We relate the Hall conductivity to the coefficient
in Kohler's like rule for magnetoconductivity and calculate some corrections
which are relevant near the intermediate temperature range ~50K (typical values
for the cyclotron frequency of the dimers). Furthermore we make a sharp
prediction that the magnetoresistance effect vanishes to order B^2 at the
temperature and magnetic field where the Hall coefficient vanishes.
