  Motivated by recent experimental reports, we carry out a Fermi liquid
many-body calculation of the interaction induced renormalization of the spin
susceptibility and effective mass in realistic two dimensional (2D) electron
systems as a function of carrier density using the leading-order
`ladder-bubble' expansion in the dynamically screened Coulomb interaction.
Using realistic material parameters for various semiconductor-based 2D systems,
we find reasonable quantitative agreement with recent experimental
susceptibility and effective mass measurements. We point out a number of open
questions regarding quantitative aspects of the comparison between theory and
experiment in low-density 2D electron systems.
