"How much of this change is due to automation? Growing income inequality could also stem from, among other things, the declining prevalence of labor unions, market concentration begetting a lack of competition for labor, or other types of technological change."

One of the most interesting hypotheticals to consider is what would have happened if U.S. workers and their unions weren't beaten in the struggle with employers in the 1970s.

Collective bargaining might have channeled innovation into qualitatively different technical paths that were more for the great majority than the path we actually went down. The major political parties might have remained accountable to working people qua working people.

David Nobel's "Forces of Production" examines one set of technical decisions - around the user interface for computer numeric control machine tools - that was seemingly made for the benefits of employers at the expense of organized workers (machinists). Whether you accept his argument in that particular instance, it raises the question of how historically contingent the design of particular artifacts might be, and to what extent they are determined by more or less historically unvarying physical or psychological ("human factors") constraints.