  The physical conditions that determine whether or not solar active regions
(ARs) produce strong flares and coronal mass ejections (CMEs) are not yet well
understood. Here we investigate the association between electric-current
neutralization, magnetic shear along polarity inversion lines (PILs), and
eruptive activity in four ARs; two emerging and two well-developed ones. We
find that the CME-producing ARs are characterized by a strongly non-neutralized
total current, while the total current in the ARs that did not produce CMEs is
almost perfectly neutralized. The difference in the PIL-shear between these two
groups is much less pronounced, which suggests that the degree of
current-neutralization may serve as a better proxy for assessing the ability of
ARs to produce CMEs.
