Who pays for Mixed-Use development?

Why should you care about MUD?  

Because MUD is everywhere, and unless you want to pay for more MUD, 

you need to know why governments and developers want it.  
If MUD isn't a financially sound development type, why build it at all?

Mixed-Use Development (MU or MUD) is the Central Planners' go-to land use style for urbanization and redevelopment for the transformation of our cities, small towns and suburbs into dense, semi-car-free communities.  Why is MU so popular?

Unlike traditional zoning where different land uses were separated by type (E.g.: General Commercial, Residential, and Industrial zones), Mixed-Use combines multiple uses in one building or alongside one another in the same zone (E.g.: apartments on the upper floors of a building that has retail and restaurants on the ground floor).  Zones don't matter much anymore.

Smart Growth and New Urbanism theories of urban planning promote MU as the dominant form of development to create compact, dense, "vibrant" urban communities where the daily needs of the residents can be met within walking and bicycling distance from their homes.  MU promotes reduction or eliminate automobiles in favor of transit that will connect these transit-oriented communities TODs) to Employment Districts and with each other.  At least that's the theory - the utopian ideal CPs are chasing.

So what is the problem with Mixed Use Development?

1.  This isn't the way the vast majority of people want to live.
2.  MU doesn't work.  MU is not economically feasible without significant public subsidies.

Why can't government depend upon the private market to take care of the supply and demand for MUD on its own?  

1.  Citizen demand for housing types isn't the way government wants people to live. 
2.  Government elites and Central Planners actively spend our tax dollars to control our lifestyles because private industry doesn't care about social engineering, only public demand (profit) for their product. 

When demand for development isn't strong enough, governments are stepping up with incentives to make MUDs happen in order to fit their urban plans.  Common methods of public subsidy/help for private developments are: local Urban Renewal districts (TIF funding), new regulations that require MU or make it easier to build, government grants, tax abatements, fee waivers, cash incentives,
transit improvements, public infrastructure (parking structures, road and utility improvements, etc.) and favorable "partnership" agreements.

The recent (May 2014) Draft Development Feasibility Analysis Report for the Tigard Triangle looked at mixed-use development at various densities and concluded that:

MIXED-USE DEVELOPMENT IS NOT ECONOMICALLY VIABLE WITHOUT PUBLIC SUBSIDIES.