  In order to provide a better understanding of rotating universe models, and
in particular the G\"{o}del universe, we discuss the relationship between
cosmic rotation and perfect inertial dragging. In this connection, the concept
of \emph{causal mass} is defined in a cosmological context, and discussed in
relation to the cosmic inertial dragging effect. Then, we calculate the mass
inside the particle horizon of the flat $\Lambda$CDM-model integrated along the
past light cone. The calculation shows that the Schwarzschild radius of this
mass is around three times the radius of the particle horizon. This indicates
that there is close to perfect inertial dragging in our universe. Hence, the
calculation provides an explanation for the observation that the swinging plane
of a Foucault pendulum follows the stars.
