Duplicate title to Caulkins, J.P., Grass, D., Feichtinger, G., Hartl, R.F., Kort, P.M., Prskawetz, A., Seidl, A., & Wrzaczek, S. (2021). The optimal lockdown intensity for COVID-19. Journal of Mathematical Economics 93 e102489. 10.1016/j.jmateco.2021.102489.