“Every leaf and every grass blade on earth makes more and more sugars as CO2 levels keep rising,” Loladze said. “We are witnessing the greatest injection of carbohydrates into the biosphere in human history―[an] injection that dilutes other nutrients in our food supply.” ... Within the category of plants known as “C3”―which includes approximately 95 percent of plant species on earth, including ones we eat like wheat, rice, barley and potatoes―elevated CO2 has been shown to drive down important minerals like calcium, potassium, zinc and iron. The great nutrient collapse, Helena Bottemiller Evich, 'Politico' 13 SeptemberThe loss seems to be of the order of 8 percent or less, but the implications for humans and for the species that eat and pollinate these plants are uncertain. (See here for a spirited debate.) Policymakers prefer to focus on variables that they can influence or control. In agriculture, the focus has been on yields: that is, the mass of crops per unit of land area. Many governments have funded agricultural extension and research institutes with the main aim of maximising yields. Reasons for this are understandable; memories of wartime shortages, for instance. For yields, cause and effect are relatively easy to identify, as are the effects of time lags. There are costs, though, which take the form of depleted soil, polluted water (pdf), loss of wildlife habitat and, as we see, nutrient depletion.
What does this have to do with social policy, or with Social Policy Bonds? Simply this: Social Policy Bonds would change policymakers' focus from things that they can influence, to problems that society wants to solve. So, rather than simply aim to maximise food production, for instance, we'd focus on improving society's health, broadly defined. If nutrient depletion worsens society's health, its effects would be captured by components of our targeted health goal including, probably, Quality Adjusted Life Years, infant mortality and longevity. It would be up to bondholders, motivated to find the most efficient ways of achieving our health goal, to work out whether, and how, to deal with nutrient depletion. No government, no single organisation, the way policy is made now, has the incentive or the capacity to address problems that we do not fully understand, using science that is inescapably out of date. Our social and physical environments are too complicated for any government to understand. Instead, they should be looking at desirable social and environmental outcomes, and setting up a system that motivates people to achieve them. If they use Social Policy Bonds, they'd be doing that, and injecting the market's incentives and efficiencies into all the stages necessary to achieve those outcomes. Focusing on any particular variable, whether it be greenhouse gas emissions, numbers of smokers, or hospital waiting times - or crop yields - just isn't good enough any more.
For more about Social Policy Bonds see here. For more about how the Social Policy Bond concept can be applied to health see here. For my views on agricultural policy see here and here.