The true multiplicity distribution of transiting planet systems is obscured by strong observational biases , leading low-multiplicity systems to be overrepresented in the observed sample .
Using the Kepler FGK planet hosts , we employ approximate Bayesian computation to infer the multiplicity distribution by comparing simulated catalogs to the observed one .
After comparing a total of ten different multiplicity distributions , half of which were two-population models , to the observed data , we find that a single-population model following a Zipfian distribution is able to explain the Kepler data as well as any of the dichotomous models we test .
Our work provides another example of a way to explain the observed Kepler multiplicities without invoking a dichotomous planet population .
Using our preferred Zipfian model , we estimate that an additional 2393 _ { -717 } ^ { +904 } planets likely reside in the 1537 FGK Kepler systems studied in this work , which would increase the planet count by a factor of 2.22 _ { -0.36 } ^ { +0.46 } .
Of these hidden worlds , 663 _ { -151 } ^ { +158 } are expected to reside in ostensibly single-transiting-planet systems , meaning that an additional planet ( s ) is expected for approximately 1-in-2 such Kepler systems .