Inside Straight

The fourth story in Poul Anderson's Conquests/Seven Conquests, "Inside Straight," has several background features in common with the same author's Technic Civilization History:

a Commonwealth;
the secondary drive;
the Anglic language;
colony planets called Hermes (in this case, Old and New);
motives for extra-solar colonization (fresh start, malcontents, ways of life).

The main point of this story is that scattered, self-sufficient colony planets would develop divergent cultures, including some odd ones. Diverse means of exchange enrich different social groups:

on New Hermes, gamblers;
on Alexander, entrepreneurs;
on Einstein, scientists;
on Hellas, the potent and beautiful;
on Arjay, politicians;
on Dromm, soldiers;
on Archbishop, philosophers?

Drommans overcoming their alien oppressors perfected the military virtues and became compelled to continue conquering. The introduction says that "...exploration and war do not always have economic causes." (Conquests, London, 1981, p. 105) Economics is basic if not always causative. If their conquests overstretch them economically, then the Drommans will have to stop, their self-image shattered, whereas, if the conquests enrich them, then this gives them a further motivation and justification.

The New Hermetian (Anderson writes "Hermesian") system:

automatic factories provide necessities free to all;
everything else is free enterprise subject to a Conservation Authority and a fair-practices act;
no expensive public works;
concentration of economic or political power discouraged;
individual liberty;
a lot of complicated economic gambling;
highly trained, commission-earning probability analysts;
therefore also, a complicated financial system with highly trained theoreticians and specialists;
consequently, highly developed games theory enabling them to win wars and defeat the Drommans.

I do not know about gambling and do not understand the phrase "inside straight"! (When I googled it, one possible meaning of the term was this story.)