New research shows unionized construction crews are more cost-efficient, on-time
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- Union-led Sacramento County projects had far smaller cost increases than non-union ones.
- Union-led projects were completed an average of two weeks faster than non-union projects.
In a recent study, researchers Larissa Petrucci and Matthew Hinkel found that Sacramento County public works projects led by unionized contractors were less expensive and more on-time than those led by non-union contractors.
The researchers’ data shows that projects led by non-union firms saw average cost increases of over $500,000 — about 10 times higher than projects led by union contractors. Union-led projects were also completed an average of two weeks faster than non-union projects.
Petrucci, a policy and research analyst at labor management organization NorCal Construction Industry Compliance, and Hinkel, an assistant professor of economics at Alma College, met as research fellows in the Institute for Construction Employment Research. Petrucci said that there is “excitement” in the field when young academics express interest in construction research, so she and Hinkel were encouraged to work together. Their findings were published this month with support from NorCal Construction Industry Compliance.
The pair began by compiling a dataset of 128 large, “relatively complex” construction projects in Sacramento County from 2018 through 2022, according to Hinkel. Each project the researchers included in the study cost $6 million or more, which ensured it was complex enough to provide substantial data. The projects were also compliant with wage requirements in California.
In 75, or 59%, of the projects analyzed in the study, the prime contractor was part of a union. In the other 53 projects, the prime contractor was not part of a union.
“Having relatively even numbers on both sides allowed us to truly be able to examine the difference between union-led and nonunion-led projects,” Hinkel said.
Does using a unionized labor force have an impact on project cost and timeliness? The researchers performed regression analysis to isolate these variables. Through these manipulations of the data, Petrucci and Hinkel controlled for external factors like project complexity, initial project cost and project location.
“Including those factors in the model gets rid of those things as other possible explanations,” Hinkel said. “If we do in fact find a difference — which we did — we can then be more confident in saying there is an actual substantive difference in cost and timeliness for a union-led versus a nonunion-led project.”
One possible reason for the differences illustrated in the study, Petrucci said, is that union contractors are “invested in training their workforce.” According to Petrucci, 92% of construction apprentices in California are trained by a union.
“When you have a highly trained worker who’s gone through years and years of both classroom and on-the-job training like that, you already have a (worker) who is particularly skilled,” Petrucci said. “We think that this may suggest why these projects can be completed faster.”
According to Petrucci, other research suggests that union-led construction projects have better safety outcomes. These more secure working conditions lead to fewer stoppages in work, also contributing to faster project completion, Petrucci said.
“We think that this is important because there are misunderstandings about what is driving costs on construction projects,” Petrucci said. “What we believe our study is able to answer is that having a workforce where contractors and employers are dedicated to training and staffing and have high safety standards does lead to more efficient productivity.”
This story was originally published July 13, 2026 at 11:00 AM.
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