We present a population synthesis calculation to derive the total number of planetary nebulae ( PN ) in the Galaxy that descend from single stars and stars in binary systems .
Using the most recent literature results on galactic and stellar formation as well as stellar evolution , we predict the total number of galactic PNe with radii < 0.9 pc to be ( 4.6 \pm 1.3 ) \times 10 ^ { 4 } .
We do not claim this to be the complete population , since there can be visible PNe with radii larger than this limit .
However , by taking this limit , we make our predicted population inherently comparable to the observationally-based value of Peimbert , who determined ( 7200 \pm 1800 ) PNe should reside in the Galaxy today .
Our prediction is discrepant with the observations at the 2.9 \sigma level , a disagreement which we argue is meaningful in view of our specific treatment of the uncertainty .
We conclude that it is likely that only a subset of the stars thought to be capable of making a visible PN , actually do .
In the second paper in this series , an argument will be presented that the bulk of the galactic PN population might be better explained if only binaries produce PNe .

The predicted PN formation rate density from single stars and binaries is ( 1.1 \pm 0.5 ) \times 10 ^ { -12 } PN yr ^ { -1 } pc ^ { -3 } in the local neighborhood .
This number is lower than the most recent PN birthrate density estimates ( 2.1 \times 10 ^ { -12 } PN yr ^ { -1 } pc ^ { -3 } ) , which are based on local PN counts and the PN distance scale , but more in line with the white dwarf birthrate densities determined by Liebert et al .
( ( 1.0 \pm 0.25 ) \times 10 ^ { -12 } WD yr ^ { -1 } pc ^ { -3 } ) .
The predicted PN birthrate density will be revised down , if we assume that only binaries make PNe .
This revision will imply that the PN distance scale has to be revised to larger values .