Analyze the full multi-delay placement family

Analyze the full multi-delay pollution-based tourism family in which the visitor-factor delay, pollution-perception delay, and visitation-driven growth and reinvestment delay are allowed to vary independently, rather than being restricted to common-delay placements.

Background

The paper studies only the eight common-delay placements obtained by restricting each of the three delay slots to either zero or the same common delay $\tau$. This restriction isolates the effect of delay placement but excludes models in which the visitor deterrence, pollution perception, and visitation-driven growth or reinvestment mechanisms have distinct delay magnitudes.

Allowing the three delays to vary independently would produce sixteen placements in the corresponding binary-delay framework. The paper explicitly identifies analysis of this unrestricted multi-delay family as unresolved.