It's hard to say without a study, but my personal opinion is that it doesn't make much difference at all in terms of getting the work done. It's only a title. What is the difference between "software engineer" and "software developer" in terms of the role? In the US, there's probably not much difference at all. In Canada, there probably is a difference because "engineer" is a more formal title denoting educational achievement, so I suspect there's a pay differential involved.