Here is an explicit example even within simple point processes. Let be a positive integer with probability mass function . The telescoping series sums to one, is finite almost surely, but . Conditional on , sample independent points with the uniform distribution on . The resulting point process has finitely many distinct points almost surely, while . Thus finite counts in each realization and finite mean counts are separate requirements; local finiteness of the intensity measure is an integrability assumption.
Let have the uniform distribution on and place a point at every , . This is a simple point process, locally finite, and a stationary point process: a translation only changes the phase modulo one, preserving its uniform distribution. For every Borel set , the Tonelli theorem gives
Its consecutive points are exactly one unit apart, despite having the same intensity measure as a unit-rate Poisson point process. This is the one-dimensional translated-grid construction.[ref]
Every half-open interval of length one contains exactly one point. For and , , each count has the Bernoulli distribution with parameter , and
More generally, an interval of length , with a nonnegative integer and , contains or points with probabilities and . Its count variance is , while a unit-rate Poisson point process has count variance .
Draw one random variable , taking values zero and two with equal probabilities. Conditional on , generate a Poisson point process on the real line with constant rate . This is a Cox process directed by the random measure : the same rate is shared by every window. It is a locally finite simple point process and a stationary point process. The law of total expectation gives ; the law of total variance and law of total covariance give, for bounded Borel sets with ,
The conditional covariance vanishes by independence, but the shared conditional means fluctuate together. This distinguishes conditional from unconditional independence.[ref]
For a window of length , the exact probability mass function is
In particular, its void probability functional is , compared with for the unit-rate Poisson point process. Whole realizations can be empty or comparatively crowded, while their mean density remains one. This example demonstrates shared-rate statistical dependence, rather than a model of short-range offspring clusters.