  We studied the field induced magnetic order in R$_{2}$Ti$_{2}$O$_7$
pyrochlore compounds with either uniaxial (R=Ho, Tb) or planar (R=Er, Yb)
anisotropy, by polarized neutron diffraction. The determination of the local
susceptibility tensor \{$\chi_\parallel,\chi_\perp$\} provides a universal
description of the field induced structures in the paramagnetic phase (2-270
K), whatever the field value (1-7 T) and direction. Comparison of the thermal
variations of $\chi_\parallel$ and $\chi_\perp$ with calculations using the
rare earth crystal field shows that exchange and dipolar interactions must be
taken into account. We determine the molecular field tensor in each case and
show that it can be strongly anisotropic.
