The main objective of this monograph is to identify theoretical and methodological foundations for measuring, assessing and optimising public aid granted to farms (at the level of EU countries and individual farms in Poland), along with an attempt of empirical verification. The auxiliary objective of the monograph is to update the ex-post analysis of the impact of subsidies on the economic, income and financial situation of these entities. Chapters: Measurement, assessment and optimization of public aid granted to agricultural holdings – selected issues. Public support for agriculture of EU countries under the CAP. Scale, dynamics and trends of changes. Implications of the direct payment degressivity mechanism in the CAP 2020+ in Poland. Subsidies and other external sources of financing activity on farms – farmers’ opinions. Subsidies vs. finance and economics of farms managed by natural persons.