Advanced Composition (Differential Privacy)
Turning arcynia's comment into an answer so this question can be marked as fixed: « The very next paragraph of the book explains this: &quot;Note that the above corollary gives a rough guide for how to set $\varepsilon$ to get desired privacy parameters under composition. When one cares about optimizing constants (which one does when dealing with actual implementations), $\varepsilon$ can be set more tightly by appealing directly to the composition theorem.&quot; That is to say, this value for epsilon does not represent anywhere near a calculated optimal value, but just a fairly good rough guide. »