Richard N Block & R. Oliver Clarke 
Labor Standards in the United States and Canada [PDF ebook] 

Labor standards and how they relate to international trade are often the subject of contentious discussions. Many argue that nations with higher standards find themselves at a competitive disadvantage against nations with lower standards. Until now there has been no way to quantify this assertion; an empirical gap existed on the relationship between labor standards and trade due to the absence of measures for labor standards that could be applied internationally. Block, Roberts, and Clarke remedy this situation by offering a method for comparing labor standards across political jurisdictions. They then apply this method to the United States and Canada, an exercise that allows them to settle the long-running dispute over whether or not Canada has higher standards than the U.S., and if so, to what degree.