New York’s construction unions are currently in the midst of a inflammatory battle with real estate developers after decades of relatively positive relations. Currently underway are daily picket lines on the Far West Side of Manhattan where construction of a $4 billion office tower has just began. Real estate developers are running anti-union advertisements in subways and newspapers. Over the last ten years, non-union contractors have gained a sizable share of the construction labor market, some workers earning just $15 an hour. According to one study published by the carpenter’s union, organized labor only makes up 65% of Manhattan projects and only 39% of projects in the other 4 boroughs. Unions have had to make significant concessions, including agreeing to a no-strike pledge, in order to compete with the nonunion contractors.
See "With Pickets and Lawsuits, Unions and Developers Go to War", Charles v. Bagli, New York Times, April 13, 2018