  We present an evolutionary disc model for the thin disc in the solar cylinder
based on a continuous star formation history and a continuous dynamical heating
of the stellar subpopulations. The vertical distribution of the stellar
subpopulations are calculated self-consistently in dynamical equilibrium. The
SFR and AVR of the stellar subpopulations are determined by fitting the
velocity distribution functions of main sequence stars. The SFR shows a maximum
10 Gyr ago declining by a factor of 10 until present time. A constant SFR can
be ruled out. The velocity dispersion of the stellar subpopulations increase
with age according to a power law with index 0.375. The new scale heights lead
to a best fit IMF with power-law indices of 1.5 below and 4.0 above 1.6 Msun,
which has no kink around 1 Msun. Including a thick disc component results in
slight variations of the thin disc properties, but has a negligible influence
on the SFR. A variety of predictions are made concerning the number density,
age and metallicity distributions of stellar subpopulations as a function of z
above the galactic plane.
