The Mechanics of Tax Increment Financing. How is the tax increment calculated in a redevelopment project? Why is redevelopment funded by TIF seldom feasible for hard core slums or blighted areas areas populated by householders with incomes far below the median, high rates of crime and many abandoned and decaying buildings? How can a redevelopment agency attract buyers of its bonds secured by property tax increments from a building before the agencys chosen redeveloper has actually completed the building?