 Hi Philip Cohn, you are giving a lecture on open science and demography at the Max Planck Institute for Demographic Research today. Why do you think demographers need to be and work open science? Well, demographers, social science generally want our research to be relevant. We want it to be accessible. We want to be able to speak to the people who want the information that we produce. And even if people can't understand everything we do, all the details of what we do, we need to signal our accountability. We have to be accountable to the people who pay for it directly or indirectly. And the way to do that is to make our work accessible, both in terms of the product itself, the papers and books and articles that we write, and in terms of the process of how we make our decisions and how we do the science.