Final answer:
The role of unions is significant in explaining the salary patterns of professional athletes. They typically negotiate higher salaries and better working conditions for their members. The effect on the number of athletes hired can vary.
Step-by-step explanation:
The role of unions in helping explain the pattern of professional athlete's salaries is generally considered significant. Labor unions, through collective bargaining with team owners and leagues, can negotiate salary caps, minimum salaries, and pension benefits. This tends to lead to higher pay for worker-members. Professional athlete unions can also work to enhance their members’ working conditions and career longevity, which can indirectly influence salary structures.
However, in terms of the quantity of workers (or athletes) hired, the impact can be mixed. A union may negotiate terms that favor more established players, but could potentially lead to a lower number of total athletes hired due to financial constraints or salary caps imposed on teams.
Comparatively, in other high-income countries, the share of workers whose wages are determined by union bargaining is often higher than in the U.S. This impacts not only the average wage levels but also the wage disparity within industries.