Card, Lemieux, and Riddell argue in their 2002 article “Unions and Wage Structure” that: They estimate that in 1981, the presence of unions reduced the variance of men's wages by 6% in the United States United States and 10% in Canada. The corresponding estimates in 1988 are 3% in the United States and 13% in Canada. Thus, they estimate that changing patterns of unionization contributed to rising wage inequality in the United States in the 1980s, but worked in the opposite direction in Canada (20). This conclusion was reached by a combination of model application and literature review, and since unions are a huge force in the United States as well as in other countries, such as Canada and the United Kingdom, it is important to determine how this result is possible . Using the theory developed around the topic of unionization, it may be prudent to use factors such as objective function, scope of bargaining, Rubenstein bargaining, all of which have a large impact on both the level of unionization in a company and the effect on implications wages. Furthermore, the relevant union and non-union factors have a strong impact on the outcome of the study, indicating that a negative change in union participation contributed to an increase in wage inequality in the private sector, both union and non-union. After an extensive review of the literature on the topic, Card and his colleagues argue that “As this discussion [literature review] makes clear, the impact of unions on the structure of relative wages depends both on which types of workers tend to be unionized and on which types of workers tend to be unionized. on how the relative wage impacts of unions vary across different groups of workers (Card, Lemieux & Riddell, 7).” This means that the demographics of workers in unions and how union wages impact these different groups are significant, including… , this balance is vanishing rapidly. Rather, the proportion of union to nonunion wages follows more of a reduced-form equilibrium model. From the foregoing analysis of the work of Card, Lemieux, and Riddell, the union theory studied in this course, and the work of other well-known economists on the topic of unions, it is evident that not only is the argument made by Card and his colleagues plausible, but that's probably a fact. From the bargaining power of unions and applying the objective function to explain why the “male over 30” demographic is declining in interest in unions to applying modeling to determine whether this change could actually create growing wage inequality across the industry , it is clear that such theory is likely to be successfully applied using models and theories.