Chris Walker has posted this draft on SSRN (forthcoming Penn L Rev).  Here is the abstract:

Federal agencies are deeply involved in legislative drafting — both in the forefront by drafting the substantive legislation the Administration desires to submit to Congress and in the shadows by providing confidential “technical drafting assistance” on legislation that originates from congressional staffers. This technical drafting assistance helps Congress avoid considering legislation that would unnecessarily disrupt the current statutory scheme by leveraging agency expertise on the subject matter. But it also allows the agency to play an active yet opaque role in drafting legislation from the very early stages. In fact, the empirical findings presented in this Article, based on extensive interviews and surveys at some twenty federal agencies, suggest that agencies provide technical drafting assistance on the vast majority of proposed legislation that directly affects them and on nearly all such legislation that gets enacted.

The under explored yet widespread practice of legislating in the shadows has important implications for administrative law theory and doctrine and the conventional principal–agency bureaucratic model. On the one hand, this phenomenon perhaps supports the growing scholarly call that agencies should be allowed to engage in more purposivist interpretation (than their judicial counterparts) because of their expertise in legislative history and purpose and their role in statutory drafting. On the other, the phenomenon may cast some doubt on the foundations for judicial deference to agency statutory interpretations, in that agencies are intimately involved in drafting the legislation that ultimately delegates to the agencies the authority to interpret that legislation. In other words, many of the agency self-delegation criticisms raised against Auer deference could apply with some force to agency statutory interpretation and Chevron deference as well. Or we should at least be considering more closely the administrative state’s role in drafting legislation — especially drafting legislation in the shadows — when considering to what degree courts should defer to agency statutory interpretations. Such reconsideration is particularly warranted in light of the transparency concerns implicated by agency legislating in the shadows.

This looks like it will be a very important paper.