This study examines policy implementation in multilevel systems as a strategic game between monitoring agencies and implementers. Focusing on the European Union's Central Monitoring System, it statistically evaluates whether compliance depends on anticipated enforcement decisions by this agency.

Data & Methods: The research analyzes empirical data from EU monitoring activities to model decision-making processes under conditions of varying enforcement success probability and sanctioning costs.

Key Question: Why does an exemplary system like the EU Central Monitoring experience compliance deficits despite high enforcement success rates?

The findings challenge conventional wisdom about its effectiveness. Our analysis shows that the agency strategically refrains from enforcing compliance when both success probability is low AND potential sanctions are high—two conditions that often co-occur.

Implication: This behavior creates a significant compliance deficit, demonstrating how monitoring agencies' strategic considerations can undermine policy implementation even in sophisticated systems like the EU.

This pattern emerges despite statistical evidence indicating nearly universal enforcement effectiveness before judicial review.