The statement that best compares the effects of absolute monarchy and constitutional monarchy is:
"An absolute monarchy is overly dependent on a single monarch, which can lead to a system that is overthrown, while a constitutional monarchy can bring long-term stability."
This statement highlights the inherent risks of absolute monarchy, where the concentration of power in a single ruler can result in instability, whereas constitutional monarchies, with their systems of checks and balances, are more likely to achieve stability over time.