The third, and most extreme, approach is to bulldoze buildings and turn them over to some alternative use, like parks or agriculture. Razing empty, dilapidated, hazardous structures is fairly uncontroversial, but more questions must be raised if the mayor is going to forcibly move significant amounts of people in order to physically reshape large land areas.
If the residents of largely empty areas aren’t willing to sell and move, then we are back in the same quandary that always faces large public changes in urban land use, like the construction of G.M.’s Poletown plant. To what extent should a city put perceived citywide interests ahead of the wishes of individual property-owners?
If removing a largely vacant neighborhood really generates significant gains, then some sizable fraction of those gains can be given to the citizens who will have to give up their homes. If generous payments, rather than eminent domain, are used to move the remaining residents, then right-sizing can be win-win.
In Atlanta, the areas that have been in decline still have people - they are just extremely poor and neglected. Think English Avenue. In Detroit, these areas are just empty. This is a fairly random Google Streetview image of Detroit - I went to Google Maps and zoomed in on residential neighborhood sort of near Downtown. This is what you get:
There has been a ton written on the decline of Detroit, but I'm not sure we in Atlanta can appreciate what is going on there. Go on Google Maps and just scroll around the satellite images - you'll see areas with half the lots just empty. This is what happens when the economic base of a region collapses in slow motion for thirty years.
So, as negative as I've been about the economic prospects for Atlanta - hey, at least we aren't Detroit!