The king's counter to his subjects' reluctance to be knighted was a general order in 1234 to all sheriffs that they should proclaim throughout their bailiwicks that all men who held one or more knights' fees in chief of the the king should procure arms and cause themselves to be knighted. ... Nevertheless it is clear that through the greater part of the thirteenth century the government was trying ... to keep in being a military form of society which was out of date. It was probably with this end in view that kings stressed the pageantry of the ceremony by which men were admitted into the order of knighthood. ... Edward I realized that knighthood must be tied to the court and the glamour of the court if young men were to be drawn into the knightly order. English society in the early Middle Ages, Pelican History of England vol 3, Doris Mary Stenton, 1965
The conceptual leap that we have to make is that knighthood in those days was a burden. It entailed an obligation to serve the king in military conflicts. It's not clear how successful was the introduction of the elaborate ritual to which Lady Stenton refers. But the principle of getting people to do things for reasons other than monetary ones is clearly long established. In this recent post I refer to research showing that under some circumstances financial incentives can actually undermine our willingness to do the right thing. How would that sit with the Social Policy Bond principle, where monetary incentives at first glance seem paramount?
Actually Social Policy Bonds are not merely a system by which all the people who help bring about social wellbing are financially rewarded. Rather it is a 'meta-system' that motivates bondholders to find the best ways of encouraging socially beneficial behaviour - whether these be monetary or not. In my book I mention the Japanese, who have carefully graded levels of respect for people according to how well they are seen to have served society. Paradoxically, holders of Social Policy Bonds would have financial incentives to devise nonfinancial ways of encouraging people to achieve our social and environmental objectives. This could be much more efficient than our current, somewhat haphazard system of rewards. And, as the Japanese and the old kings of England knew, it could be much less expensive.