The Ricci sectional curvature

Question

Let $(M,g)$ be a riemannian manifold with Ricci curvature $ric$ as a bilinear form. The Ricci sectional curvature $\rho$ is:

$$\rho (X,Y)= \frac{ric(X,X)ric(Y,Y)-ric(X,Y)^2}{g(X,X)g(Y,Y)-g(X,Y)^2}$$

Are the manifolds of constant Ricci sectional curvature, Einstein manifolds?