Anyone who thinks choices can be made based solely on data should listen to this segment in the wonderful radio show "RadioLab". They tell a story of a man ("Elliot") whose emotional center was accidentally removed in surgery leaving him only the ability to make choices based on cold-hard data.

It is interesting to see how all the data impedes his ability to decide. The problem isn't not enough data, the problem is which data matters more? That involves a value system which at a very root level, requires morals and emotions to make the call (or at least break a tie).