questions for a social stock market

Thinking about Social Impact Bonds led us to a long discussion that essentially tried to describe a new stock market in which investors tried to choose between these bonds. The hurdle implicit in this is trying to find a way to measure the amount of social impact of one bond versus another when the two social bonds are for completely different types of social benefit.

Measuring social impact can be very subjective, but our interests are just as subjective, so perhaps that doesn't matter. Presumably, everyone interested in social change has a particular area to which they are partial. Social innovators don't go into social innovation for the money, they go into it because they've chosen an area in which they'd like to see social change. The same may be true for investors in the social stock market. It may not be necessary to find an overarching way to compare all types of social impact. We talked about the possibility of different categories for different types of impact, like perhaps environmental, housing, poverty, etc. Wouldn't this be enough, since people will choose what they are partial to, or what they have a personal interest in anyway?

Even trying to compare social value within one social problem is problematic. We tried to discuss it through an economic perspective, seeing the value in terms of the supply and demand. But how can you quantitatively determine the demand for a given social problem? We can say there is a large or small demand, but can we pinpoint the demand precisely enough to be able to form an equation that will give us the amount of social value a social project can achieve? And given that we could, do we even want to think of social value economically?

It's hard to believe that a social stock market would ever turn into a cutthroat market where investors were in it just for the returns, so perhaps we shouldn't treat it as such. Or maybe it's the other way around, maybe we shouldn't treat it as a cutthroat market to prevent it from becoming one. Either way, perhaps it's in our best interest to allow a bit of subjectivity by limiting our comparisons of social impact to projects that deal with the same social problem.