  The current transport in polycrystalline MgB$_2$ is strongly influenced by
the intrinsic anisotropy of this superconductor. Untextured bulks and wires are
macroscopically isotropic, but the grains retain their anisotropic properties
and the field dependence of the critical currents is much stronger than in
isotropic superconductors. Weakly or partially textured tapes are
macroscopically anisotropic, but the anisotropy of the zero resistivity (or
irreversibility) field is smaller than the intrinsic upper critical field
anisotropy, $\gamma$. The \Jc-anisotropy is field and temperature dependent and
can be much larger than $\gamma$. The most suitable parameter for the
quantification of the macroscopic anisotropy is, therefore, the anisotropy of
the zero resistivity field. It is difficult to distinguish between a higher
degree of texture at a lower intrinsic anisotropy and a weaker texture at
higher anisotropy and hardly possible based on the field dependence of the
critical current anisotropy alone. The knowledge of the upper critical field is
crucial and angular resolved measurements of either the critical currents or,
better, the resistive in-field transitions are favorable for this purpose.
