Testing variations on radial scale length, stellar density at Sun position, and SFH. Cepheid counts for the same completeness regions as Fig. 5. The green line indicates the observational counts, the grey region is the region within 1σ. Notice how DAV (changed scale length) and DM (default model) are really close to the observational data. The simulations have been made taking into consideration the Marshall et al. (2006) extinction model. Hence reasonable changes in the radial scale length have small effects in the total Cepheid counts. DBV (local stellar density variant) is still close to observational data. As expected, a change in SFH (DCV) is critical for the comparison of Cepheid counts in absolute terms.