Table 1.

Simulation results for β estimation under SPGLM data–generating mechanisms and PLLM and SPGLM models

True f0	Model	Mean		RMSE		CP
		0	1	0	1	0	1
	True β	– 0.7	0.2	—	—	—	—
Truncated Poisson	SPGLM	– 0.708	0.199	0.090	0.087	0.957	0.959
	PLLM	– 0.707	0.199	0.090	0.086	0.956	0.959
0-Inflated Poisson	SPGLM	– 0.703	0.200	0.107	0.103	0.947	0.949
	PLLM	– 0.703	0.200	0.107	0.102	0.904	0.921

RMSE: root mean square error; CP: coverage probability for 95% Wald confidence interval. True f₀ values are given in Table 2.