  Gravitational waves inform about the probable distances at which an observed
signal originated. This information when combined over multiple observations is
used in the modeling of the redshift evolution of the merger rate. This is an
important aspect of binary black hole population analysis which is expected to
have close ties with the star formation history of the universe or dynamical
evolution of star clusters. At the least, it can probe the time delay between
the star formation and merger of remnants. However, due to the degeneracy
between the inclination angle of the binary and the luminosity distance, the
measured luminosity distance has large uncertainty that limits our ability to
precisely measure the redshift distribution of mergers. In this letter, we show
that by imposing the cosmological principle it is possible to suppress this
uncertainty and better discriminate between different distributions modeling
the redshift evolution of binary black hole merger rate. Additionally, we show
that by making a comparison with an analysis that does not make such imposition
we can probe the cosmological principle.
