Laminar theories of electrojet dynamics predict that the primary eastward electric field is almost constant with height. Nevertheless, according to previous findings of the authors, the electrojet intensity predicted by these theories agrees with the measured one only if that component of the electric field is assumed to be almost half its measured F region value at E region heights. In the present paper this apparent contradiction is investigated further by contrasting the physical hypotheses on which theoretical models rely with empirical data and taking into account the turbulent contribution to the Pedersen conductivity as proposed by Rogister (1971). It is found that turbulence due to either gradient drift or two-stream instabilities, or both, reduces the secondary electric field by increasing the Pedersen conductivity from 30% to 100% of its laminar value within almost all the E region, and that the geomagnetic field lines seem not to be equipotential, a result that cannot be explained within the framework of present theories. ¿ American Geophysical Union 1989