The identification of average causal effects of a treatment in observational studies is typically based either on the unconfoundedness assumption or on the availability of an instrument. When available, instruments may also be used to test for the unconfoundedness assumption (exogeneity of the...

The identification of average causal effects of a treatment in observational studies is typically based either on the unconfoundedness assumption or on the availability of an instrument. When available, instruments may also be used to test for the unconfoundedness assumption (exogeneity of the...

Acknowledgements -- Introduction / ASHOK MISHRA, DAVIDE VIAGGI, AND SERGIO GOMEZ-Y-PALOMA -- The relationship between farm families and the structure of agriculture / MARY C. AHEARN AND WALTER ARMBRUSTER -- Influence of cap on social sustainability in Greek and Bulgarian rural areas / D....