The impact of large-scale social media advertising campaigns on COVID-19 vaccination: Evidence from two randomized controlled trials.

[1 ] Department of Economics, MIT; 77 Massachusetts Avenue, Cambridge, MA 02139, USA.

[2 ] Department of Economics, Harvard University; 1805 Cambridge Street, Cambridge, MA 02138, USA.

[3 ] Department of Economics, Stanford University; 579 Jane Stanford Way, Stanford, CA 94305, USA.

[4 ] Massachusetts General Hospital, Department of Medicine, Neuroendocrine Unit, Department of Pediatrics, Endocrinology, Boston, MA, USA.

[5 ] 55Bd Diderot CS 22305, 75610 Paris CEDEX 12 France.

[6 ] School of Management, Yale University; 165 Whitney Avenue, New Haven, CT 06511, USA.

[7 ] Lynn Community Health Center, Lynn, MA 01901, USA.

[8 ] Johns Hopkins University, School of Nursing, Baltimore, MD, USA.

[9 ] Abdul Latif Jameel Poverty Action Lab (Europe); 48 Boulevard Jourdan, 75014 Paris, FRANCE.

[10 ] Massachusetts General Hospital; 55 Fruit Street, Boston, MA 02114, USA and University of California, San Francisco (UCSF); 505 Parnassus Ave, San Francisco, CA 94143, USA.

[11 ] Massachusetts General Hospital for Children, Department of Pediatrics, General Pediatrics, Boston, MA 02114, USA.

[12 ] Massachusetts General Hospital; 55 Fruit Street, Boston, MA 02114, USA.

[13 ] Harvard Kennedy School of Government; 79 John F. Kennedy Street, Cambridge, MA 02138, USA.