I was invited to answer the question above at Quora, which touches on a number of themes on this blog. It generated an interesting discussion, and I reproduce my answer here:

This Venn diagram explains the most fundamental barrier:
If you squint, you might be able to find a couple of intersections, but not many. I think that this is a problem that can be solved largely by providing a clean, obvious, technical solution for lawmakers. To borrow from the Godfather: offer legislators a solution they can't refuse (more below).

But this question asks about the non-technical* barriers, and these are largely inertial. The legal community is unaware of the powerful text-based tools that could make legal work more accessible to the public and more efficient. Meanwhile, there is no "version control" lobby in Congress. So although adding version control would make a tremendous difference to the efficiency of the legal process, few people understand the value that it would bring. I've written about the potential benefits in a couple of specific cases: What can lawmakers learn from computer science? and Open Source Tax Law

Much of the current system for drafting, publishing and updating U.S. laws is more than two hundred years old, depending on how you count. It is internally consistent (mostly) and is actually quite sensible for organizing legislation into printed books.**

In the case of U.S. Federal legislation, the significant burden of writing, compiling and publishing U.S. laws is divided among three different institutions:  the Office of Legislative Counsel of the U.S. House is in charge of formatting and printing legislative drafts and proposed legislation; the Law Revision Counsel of the U.S. House maintains and updates the U.S. Code on a 6 year schedule***; and the Government Printing Office is in charge of printing the official version of the U.S. Code. When these roles were originally established, they provided the human resources and Quality Assurance to maintain an organized body of law. The challenge is to move from this system to one that is suited for an electronic age.

Each of the three institutions works with legislation in a different primary format. Where metadata has been added, e.g. to create an XML or HTML version, the formats are not consistent with each other. This is a technical barrier that will require a non-technical solution (choosing one format and responsible institution over the other). It's a question of awareness and political will.

This year has seen some progress on both counts. Just a couple of months ago, Speaker of the House John Boehner and majority leader Eric Cantor wrote a letter to the Clerk of the House, calling for e-formats for legislation.**** The Sunlight Foundation has been doing great work in pushing for transparency in government, including more consistency in e-formats for legislation.

This is where I think a technical solution (and technical people) can make a difference. We can develop a solution that "just works": showing a redlined version of laws for any bill, accurately showing changes in the U.S. Code as soon as an amendment is enacted, and browsing of legislative history like the MacOS Time Machine. A non-partisan solution that could save money and increase transparency, all at the push of a button. I still wouldn't underestimate the power of inertia, but having an elegant and simple technical solution close at hand will make it much more likely that legislators will make the change.

*By "technical" I assume the question refers to the algorithm that would actually be used to implement version control, and "non-technical", I assume, means the political or historical resistance to change.

**Legislators, and the legal community as a whole, has yet to make the transition from print-centered formatting to electronic. Legal documents--even if originated and consumed electronically--are still formatted as if destined primarily for print.

***The U.S. Code is a compilation of U.S. Federal laws into 50 Titles, divided by subject area. https://www.house.gov/house/laws....

****I highlight this letter, and some of the technical challenges to converting legislation into a version-control friendly formats, on my blog:https://blog.tabulaw.com/2011/04/...

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