From the announcement:
Starting in 2010, the Econometric Society will publish two new journals, called Quantitative Economics and Theoretical Economics. These will be open access journals, meaning that electronic access will be free for both members and non-members of the Society. Each journal will have its own Editorial Board, with an Editor, several Co-Editors, and a set of Associate Editors. The rules for appointment of the members of the Editorial Board will be identical to those used for Econometrica. Governance of the new journals will, again, be identical to the governance of Econometrica.
Despite these similarities, it is expected that each new journal will develop its own identity. While the new journals will have very high quality requirements, they may experiment more with publishing papers in new research areas. Nevertheless there will be scope for collaboration between the three journals, which will be discussed in a committee that includes the three Editors. . . .