<i>I did not suggest that they have little agency around population control. What I suggested was that aliens will continue to want to have children</i><p>So you suggested that their civilization as a whole had little agency around population control.<p><i>Beyond that, if you have effectively infinite space and resources, there&#x27;s no need at all to have even the slightest bit of population control.</i><p>You&#x27;re forgetting simple geometry. Space empires can only expand proportional to n^3, while their population could potentially expand proportional to k^n. Also, in a situation where there are multiple star-faring &quot;species,&quot; a hegemonic, exponentially expanding entity might well be viewed by others as worse than obnoxious.