Model I:	(1) εia = μi + νia
	(2) νia = ρνi, a−1 + ηia
Model II:	(1), (2), plus
	(3) ηia = ξia + θξi, a−1
Model III:	(2), (3), plus
	(1′) εia = μia + νia
	(4) μia = μi, a−1 + ωia
	with ${\mathrm{\sigma }}_{\mathrm{\mu }}^2=\text{Var}({\mathrm{\mu }}_{\mathrm{i}1})$
Model IV:	(2), (3), plus
	(1″) εia = μi + aϕi + νia