  We have carried out a new evaluation of the eighth-order contribution to the
electron g-2 using FORTRAN codes generated by an automatic code generator
gencodeN. Comparison of the "new" result with the "old" one has revealed an
inconsistency in the treatment of the infrared divergences in the latter. With
this error corrected we now have two independent determinations of the
eighth-order term. This leads to the revised value 1 159 652 182.79 (7.71) x
10^{-12} of the electron g-2, where the uncertainty comes mostly from that of
the best non-QED value of the fine structure constant alpha. The new value of
alpha derived from the revised theory and the latest experiment is alpha^{-1} =
137.035 999 084 (51) [0.37 ppb], which is about 4.7 ppb smaller than the
previous alpha^{-1}.
