  We developed a theory of electric and thermoelectric conductivity of lightly
doped SrTiO$_3$ in the non-degenerate region $k_B T \geq E_F$, assuming that
the major source of electron scattering is their interaction with soft
transverse optical phonons present due to proximity to ferroelectric
transition. We have used kinetic equation approach within relaxation-time
approximation and we have determined energy-dependent transport relaxation time
$\tau(E)$ by the iterative procedure. Using electron effective mass $m$ and
electron-transverse phonon coupling constant $\lambda$ as two fitting
parameters, we are able to describe quantitatively a large set of the measured
temperature dependences of resistivity $R(T)$ and Seebeck coefficient
$\mathcal{S}(T)$ for a broad range of electron densities studied experimentally
in recent paper [1]. In addition, we calculated Nernst ratio $\nu=N/B$ in the
linear approximation over weak magnetic field in the same temperature range.
