Tilly’s book “Durible Inequality” argues that the group forming emerges almost entirely because the creation of a group boundry helps to lower the transactions costs of inside the organizational activity.

It is easier on a moment to moment basis to use existing catagory boundaries to quickly solve organizational problems. For example answer the question “What search engine will I use to look up X.” with the reply “Google” than it is to pause and select from Google, AllTheWeb, A9, or Ebay. It is a time saver to join the Google club, to shun the other search engines. Club loyalty.

But wait. Tilly is writing a book about inequality. Casual use of category boundaries has another name – prejudice. He is interested in the cases where this process goes both bad and becomes rigid.

He states that groups capture two powers which may lead to abuse.

• The ability to engage in Opportunity Hording.
• The power to Exploit others.

Efficiency isn’t on that list. Efficiency isn’t about the abuses that may occur. The abuse doesn’t arise from one group out performing another.

Hording opportunities is a game all groups can and do play. Even very weak groups. One of his examples is immigrant cleaning ladies. When knowledge of job opportunities arise they tend to pass then along the social networks of their immigrant community. That alone, tends to lead to each city having one ethic group that is renown as having the knack for house cleaning. Polish ladies in Chicago; Brazilians in Boston.

Exploitation is the means of the powerful. The powerful can force it’s will on other (by definition subordinate) groups. Exploitation is not limited to opportunity hoarding. It is the use of force to actively deny the options to other groups. To force their choices.

Consider the classic scenario where 90% of a town’s business deals are made is the all while, all male, golf club. Is that opportunity hoarding or exploitation?