Agri-environmental programmes should be designed, implemented and evaluated on the basis of the use of the acquis of the new welfare economics, and in particular its part referred to as cost-benefit analysis. Then, there is a chance that the public goods and internalised externalities offered by the farmers will be optimised. Subsequently, it will be possible to properly define the increase in total costs and the effects occurring in the farms that choose to participate in the available agri-environmental projects. This means that the rates of payments to farmers for agri-environmental services will be calculated on an objectified basis. In a larger scope, it will be possible then to rely on the diversity of rates of remuneration of farmers. This way, it will be possible to improve cost and allocation efficiency of the programmes themselves and to streamline public expenditure incurred on the agri-environmental policy and to reduce the welfare losses caused by taxation.