A proposed acquisition of a multifamily 'value add' project has a capitalization rate of 7%, and project Un-levered IRRs of 10% over five years. However, you are told that the acquisition could be done with the following capital structure: 60% 1st mortgage debt at an 8% rate, 10% mezzanine debt at an 11% rate, and 30% equity. With the new capitalization, the levered returns are projected to be 15% over five years. Given that the first mortgage debt and mezzanine debt rates are higher than the capitalization rate, why is the levered IRR (15%) higher than the unlevered IRR (10%)?