The trick is to teach people to express their values by
consumption, not by
production or
investment. Most people have the intuitive sense that they are a moral person when they personally don't perform any acts they consider immoral. This sense fails when they can pay someone to perform an action that they would consider immoral but with a consequence they desire, all without their knowledge.
The one place, in a capitalist market economy, where values have a place is in the endpoint, at the consumer. Consumer markets really depend only on values; by definition, they are those goods that people buy because they value them inherently, not those that they buy to achieve another goal. The rest of the economy self-adapts to produce those goods as efficiently as possible, which often means production practices that people would find morally repugnant.
If people trained themselves to a.) seek out as much information as possible about the supply chains of the companies they buy from and b.) not buy from them if the externalities introduced by the company aren't in accord with their values, then the market would self-adapt to reflect those preferences. It effectively creates a market for intelligent entrepreneurs to do the right thing, by influencing consumption desires so that there's a profit potential in being good.
There are still some very significant challenges in bringing this information to the consumer, and in people integrating all that information into their choices. A lot of the benefits of market economies is that they condense a lot of information from each stage of the production process into one number, a price, which propagates throughout the value chain so that self-interested actors end up producing a good in the most maximally efficient way. If you want to encode moral judgments and pass them through the value chain, you need a lot more information to go from producer to consumer. And businesses have a lot of incentive to cheat and conceal this information, so accurately recording & transmitting it is challenging.
Actually, I just had a crazy half-baked idea around using vectors instead of scalars for prices and encoding this information in a cryptocurrency, but the margin of this HN comment is too small to contain it. Maybe someone else can run with it.