  The status of the Bjorken sum rule is examined in the light of recent data on
the spin structure functions of the deuteron and proton obtained by the SMC
group, the neutron by the E142 group and the proton by the E143 group.
Combining the new data with that already obtained for the proton by the EMC
group and SLAC/YALE collaborations, we show that the Bjorken system of
equations is violated at the 2-3 sigma level. We also discuss in detail the
role of possible higher-twist contributions and higher-order PQCD corrections.
