Union Contractors Complete Public Projects Faster, Study Finds

New research found union-signatory contractors delivered projects faster while keeping cost increases significantly lower.

A new study of 128 Sacramento County public works projects found that union-signatory contractors consistently delivered better project outcomes than non-union contractors, completing projects faster while keeping cost increases significantly lower.

The research adds to growing evidence supporting the ⁠benefits of Project Labor Agreements (PLAs), particularly on complex public construction projects where predictable schedules, skilled labor and cost certainty are critical.

Researchers analyzed infrastructure, school and government building projects completed between 2018 and 2022. Every project was built under California’s prevailing wage law, allowing researchers to compare performance between union-signatory and non-union prime contractors under similar labor standards.

If you’re new to the topic, learn more about ⁠what a Project Labor Agreement is and why many public owners use them on large construction projects.

Union contractors outperformed non-union contractors

Researchers reviewed 128 public works projects with an average original value of approximately $6.5 million and found measurable differences in both cost control and project schedules.

Among the study’s findings:

• Union contractors completed projects up to 22 days faster than non-union contractors.
• Projects led by non-union contractors experienced average cost increases of more than $500,000, more than ten times higher than projects led by union-signatory contractors.
• After controlling for project size, location and construction type, union-signatory contractors reduced cost growth by 4.9% to 6.4%.
• Statistical analysis found union contractors shortened project completion times by 14% to 22%, or approximately 38 to 60 days.

Researchers noted these results persisted even though union-signatory contractors often managed larger and more complex public construction projects.

Why project labor agreements matter

The authors point to several factors that help explain the results, including workforce stability, access to highly trained skilled trades workers, registered apprenticeship programs and stronger safety performance.

Construction labor represents only about 23% of total public works construction costs, while delays, labor shortages, rework and safety incidents can dramatically increase overall project costs and completion times.

Those findings closely align with many of the advantages commonly associated with ⁠Project Labor Agreements, including improved workforce coordination, reliable staffing, consistent training standards and fewer project disruptions.

For additional background, visit our ⁠Project Labor Agreement FAQ, which answers many of the most common questions about how PLAs work and when they are used.

You can also browse the latest ⁠Project Labor Agreement news and research covering legislation, construction trends and public policy developments from around the country.

About the study

The report, Union Contractors and Project Management Outcomes: Cost and Timeliness on Sacramento County Public Works Projects, was authored by Dr. Larissa Petrucci, a policy and research analyst at NorCal Construction Industry Compliance (NCIC), and Dr. Matthew Hinkel, assistant professor of economics at Alma College.

Using publicly available Sacramento County data, the researchers evaluated projects completed between 2018 and 2022 and applied industry-standard regression analysis to account for differences in project size, location and construction type.

The authors concluded that union-signatory contractors consistently delivered stronger project management outcomes, reducing cost increases while improving schedule performance compared with non-union contractors.

Readers interested in the complete analysis can review the ⁠full research report. A summary of the findings is also available from the ⁠National Law Review.