The Treasury Department has issued a solicitation notice for tax statistics research for the IRS's Statistics of Income Division:

The SOI requires high quality proposals for research projects that would necessitate access to federal tax microdata and are for statistical puposes, not tax compliance. A proposal should explain why it is not feasible to conduct the proposed research by using aggregate tax data – either from a special tabulation that SOI might produce or from existing publicly available data, including the SOI Individual Public Use File (PUF). Please review attached solicitation package for full details.

For this statement of work, consideration will be given only to proposals involving research on statistical methodologies, international income and taxation, non-profit organizations, estate and/or gift taxation, individual income taxation related to unincorporated businesses (except partnerships), or individual taxpayers with retirement accounts. In addition to describing the research merits of a project that will result in presentations/publications for professional conferences and journals, a proposal should specifically address the researcher’s familiarity with SOI, including the required data and metadata. A proposal must also address specific contributions to SOI’s staff development program, such as through the researcher’s mentoring and/or collaborating with SOI staff.