Average starbirth parameter, b, for selected cluster mergers as a function of time since infall, where infall is defined as the time corresponding to the peak of mass accretion. During the early stages of the merger – up to approximately 500 Myr after infall – the starbirth parameter exceeds unity, indicating a period of enhanced star formation. Following this phase, b declines decreases even below one, consistent with a suppression of star formation activity.