Reputation should solve this problem given that life is a repeated game as long as we also are able to be long-sighted. A more formal argument can be found here: http://economics.mit.edu/files/4754

That suggests the cultural problem is decline in longer-term thinking or more likely a decline in arbitrary codes of behavior without a concomitant increase in longer-term thinking that would recreate many of those same norms.

American business used to place a high value on trust: "A man I do not trust could not get money from me on all the bonds in Christendom. I think that is the fundamental basis of business." -J. Pierpont Morgan

As another example, Warren Buffet seldom does diligence to determine an offer; he trusts those from who he buys to deal and report honestly.