Allan,
I think you will find many people who will dissagree with you on this, including Brad. (And me, of course). This isn't a matter of "being consistant" between these two production types. The production of a social project can be stopped and another one started without loosing the work done on the first project. Then you can switch back to it later and continue from where you left off. This is practiacl in a "real world" sense because a social project improves real estate, that is, it takes up land. If another social project becomes critical the first one sits on the land it was started on while the other one is being buit (on another piece of land). The support for building ships, however, is much different. They are, in our real world, built in docks. Switching to another ship before finishing the current one requires dismantling and salvaging the current ship. The salvage then goes into building the new ship. I have seen Brad discuss the rationale for not penalizing someone for changing ship porjects, but I think it boils down to simpler code not to.