The only long-term justification for future expenditure of taxpayers’ money in the agricultural sector is the provision of public benefits. Payments should represent the most efficient means by which society can purchase the public ‘goods’—environmental, rural, social—it wishes to enjoy. For these payments to remain publicly acceptable, it is essential that they relate directly to the public goods provided and that, in turn, these public goods are measurable and capable of evaluation.That would certainly be an improvement on the current nonsense, but how far would even that vision take us? It would probably take us into the realms of 'multifunctionality', whereby farmers and their lobbyists identify such nebulous by-products of agriculture as employment in rural areas, or the failure of farmers totally to destroy wildlife everywhere in Europe, and demand payment for supplying them. If this sounds cynical, it's not: agriculture's 'multifunctionality' is a means by which large quantities of taxpayers' and consumers' funds are already siphoned off to farmers and agribusiness in the European Union. As if agriculture alone is multifunctional! You might also cite the mutlifunctionality of violent crime or arson - they generate employment for health care personnel, construction workers, ambulance drivers and the rest. There's a case for looking at net positive multifucntional benefits, but it's a difficult and inescapably subjective one, especially if other sectors were to start demanding equal treatment.
There is another way: immediately announce the phasing out of all subsidies to farming to be completed in ten years. Use the taxpayer funds saved to alleviate genuine poverty, and allow consumers to benefit from lower food prices. One result would be a drop in the value of farmland. This would relieve stress on the environment and allow more people to take up farming. You would see a substitution of capital by labour, and quite possibly an increase in total production, though that would not be an explicit policy goal. Then would come the time to take on baod some of the UK House of Commons report: identify any further goals, social or environmental, that the public is willing to pay for, and reward people, perhaps by issuing Social Policy Bonds, for achieving them.