Is there a connection between safety and union vs. non union jobs?

Is there a relation between the recent spike in construction accidents and whether or not these are union or non-union projects? New York City officials want to know. A working theory is that this is because of a difference in union vs. non-union safety regulations. Damning statistics show that not only that more projects in the city are coming from non-union companies, but also that work related accidents in the construction field have gone up in the past two years. This has been highlighted after the recent spike in housing construction in the city. This is coupled with a rise in things like work-stop orders and recorded injuries. Officials are asking that sites and accidents start being recorded as union or non-union to create a way of monitoring the theorized source of these accidents. “The number of construction site incidents increased over the past two years, with 433 accidents and 471 injuries on work sites last year, according to Department of Building figures cited by the New York Daily News. That’s around double what it was in 2014. The city also counted 12 construction site fatalities last year, up from eight in 2014.”, as quoted from an article on The Real Deal, a New York Real Estate website.

Please see the articles posted below for more information.

NYC official urges city to classify construction site accidents as union or nonunion
WSJ: NYC construction unions ‘losing their grip’ on private market
EXCLUSIVE: NYC urged to release info on construction accidents to show whether union jobs are safer
Council committee wants city to record data on accidents at union, nonunion sites