  We construct an effective action for Polyakov loops using the eigenvalues of
the Polyakov loops as the fundamental variables. We assume Z(N) symmetry in the
confined phase, a finite difference in energy densities between the confined
and deconfined phases as $T\to 0$, and a smooth connection to perturbation
theory for large $T$. The low-temperature phase consists of $N-1$ independent
fields fluctuating around an explicitly Z(N) symmetric background. In the
low-temperature phase, the effective action yields non-zero string tensions for
all representations with non-trivial $N$-ality. Mixing occurs naturally between
representations of the same $N$-ality. Sine-law scaling emerges as a special
case, associated with nearest-neighbor interactions between Polyakov loop
eigenvalues.
