This is a genuinely contested question in economics, with legitimate research supporting different conclusions depending on what outcome you're measuring. Here's a balanced breakdown:
Arguments that unions are beneficial
For individual workers:
•Unions generally raise wages for their members, often called the "union wage premium"—historically estimated in the range of 10-20% compared to similar non-union workers.
•They tend to compress wage inequality by raising pay more for lower- and middle-wage workers than for higher earners, and often provide better benefits (health insurance, pensions) and job security protections.
•Unions can improve workplace safety and give workers a formal voice/grievance process, reducing arbitrary firing and improving working conditions.
Broader economic/social effects:
•Some research links the decline of private-sector unionization in the U.S. since the 1970s to rising income inequality, since unions historically helped sustain a larger middle class.
•Unions can increase productivity in some settings by reducing turnover, improving morale, and giving workers an institutional channel to raise concerns (rather than just quitting).
•They contributed historically to broader labor standards (minimum wage, 40-hour week, workplace safety laws) that benefit even non-union workers.
Arguments that unions can be harmful or have mixed effects
Potential costs to the economy/firms:
•Higher union wages, if not matched by productivity gains, can raise labor costs and potentially reduce firm profitability, investment, or hiring—especially in competitive or declining industries.
•Some studies find unions associated with slower employment growth at unionized firms, as rigid work rules or higher costs can push companies toward automation, outsourcing, or relocation.
•Strikes and work stoppages can impose short-term disruption costs on the broader economy.
Effects on non-union workers:
•Higher union wages in one sector can sometimes "crowd out" opportunities elsewhere, as displaced capital or labor shifts to non-union sectors, potentially suppressing wages there.
•Rigid seniority rules in some union contracts can reduce flexibility and sometimes disadvantage newer or younger workers.
The honest takeaway
Economists broadly agree unions raise wages and reduce inequality for their members, but disagree on net effects for overall employment, productivity, and growth. The impact depends heavily on:
•the industry and its competitiveness,
•whether unions and management have an adversarial or cooperative relationship,
•the broader economic context (e.g., in strongly unionized, less globally exposed sectors the costs tend to be smaller; in highly competitive, trade-exposed industries, the costs can be larger).
Most mainstream economists would say unions provide clear benefits to their own members in wages, benefits, and job security, while effects on the broader economy are more ambiguous and context-dependent—some models show productivity/efficiency gains from reduced turnover and better worker voice, while others show costs from rigidity or reduced competitiveness.
If you want, I can dig into specific studies (e.g., on U.S. manufacturing, Nordic-style sectoral bargaining, or recent organizing trends) for a more data-driven comparison.