As controversy surrounding conduct in the Australian building industry intensifies, an economist representing a major construction sector lobby group has linked what he says is a return to thuggish behaviour on sites since the abolition of a key regulator with a decline in the industry's productivity.

In a statement released on Wednesday, Master Builders Australia Chief Economist Peter Jones says following a sluggish period throughout the 1990s, ABS data shows that the nation’s construction sector outperformed the broader economy in terms of productivity gains from the period spanning the start of the Cole Royal Commission in…