Recent studies have forecasted major growth in mobile broadband traffic. Due to the predicted high growth rate of mobile broadband traffic over the coming years (demand), there is a need for more wireless network capacity (supply). One of the major approaches to expand mobile wireless capacity is to add more spectrum to the market by enabling "spectrum sharing". The FCC has issued many reports indicating that the US is dangerously close to running out of capacity for mobile data, which is why the FCC and the NTIA have been working continually to enable spectrum sharing. Spectrum sharing has moved from being a radical notion to a principal policy focus in the past decade. Enabling spectrum sharing regimes means that sharing agreements must be implemented.To have meaning, those agreements must be enforceable. The focus of this paper is to determine the relationship between enforcement methodologies and benefits of spectrum sharing through sharing between government and commercial users. Sharing between the government incumbents (i.e. Federal or non-Federal agencies) and commercial wireless broadband operators/users is one of the key forms of spectrum sharing that is recommended by the NTIA, the FCC, and the PCAST report. To address this problem, we build a model to quantitatively examine the relationships between different enforcement scenarios and sharing benefits. We model two case studies, 1695-1710 MHz band and 3550-3650 MHz band.