  "Power Law Cosmologies" are defined by their growth of the cosmological scale
factor as $ t^\alpha$ regardless of the matter content or cosmological epoch.
Constraints from the current age of the Universe and from the high redshift
supernovae data require ``large'' $\alpha$ ($\approx 1$). We reinforce this by
latest available observations. Such a large $\alpha$ is also consistent with
the right amount of helium and the lowest observed metallicity in the universe
for a model with the baryon entropy ratio $\approx 8.1\times 10^{-9}$.
