  From the galaxy power spectrum in redshift space, we derive semi-analytical
results on the generic degeneracy of galaxy clustering measurements. Defining
the observables $\bar{A}= Gb\sigma_8$ and $\bar{R} = Gf\sigma_8$, (being $G$
the growth function, $b$ the bias, $f$ the growth rate, and $\sigma_8$ the
amplitude of the power spectrum), we perform a Fisher matrix formalism to
forecast the expected precision of these quantities for a Euclid-like survey.
Among the results we found that galaxy surveys have generically a slightly
negative correlation between $\bar{A}$ and $\bar{R}$, and they can always
measure $\bar{R}$ about 3.7 to 4.7 times better than $\bar{A}$.
