Investing for Discovery and Sustainability in Astronomy in the 2020s

As the next decade approaches, it is once again time for the US astronomical community to assess its investment priorities for the coming decade on the ground and in space. This report, created to aid NOAO in its planning for the 2020 Decadal Survey on Astronomy and Astrophysics, reviews the outcome of the previous Decadal Survey (Astro2010); describes the themes that emerged from the 2018 NOAO community planning workshop "NOAO Community Needs for Science in the 2020s"; and based on the above, offers thoughts for the coming review. We find that a balanced set of investments in small- to large-scale initiatives is essential to a sustainable future, based on the experience of previous decades. While large facilities are the "value" investments that are guaranteed to produce compelling science and discoveries, smaller facilities are the "growth stocks" that are likely to deliver the biggest science bang per buck, sometimes with outsize returns. Investments in data-intensive missions also have benefits to society beyond the science they deliver. By training scientists who are well equipped to use their data science skills to solve problems in the public or private sector, astronomy can provide a valuable service to society by contributing to a data-capable workforce.