In this note we prove the following law of the iterated logarithm for the Grenander estimator of a monotone decreasing density: If
f(t0)>0,
f′(t0)<0, and
f′ is continuous in a neighborhood of
t0, then
almost surely where
here
G is the two-sided Strassen limit set on
R. The proof relies on laws of the iterated logarithm for local empirical processes, Groeneboom’s switching relation, and properties of Strassen’s limit set analogous to distributional properties of Brownian motion; see Strassen
[26].