Excerpt] But the immediate question I am addressing is how the practice of double-breasting undermines the stability of collective bargaining in the construction industry. The simple answer is that it is not exceedingly difficult for a unionized contractor to operate a double-breasted nonunion firm and, given the increasingly intense competitive pressures to cut labor costs (given rising land and material costs), employers have a strong incentive to double-breast. To the extent unionized contractors have pursued that business strategy, how has it impacted the system of collective bargaining in the construction industry