Bryan T. Camp (Texas Tech) has published The Unhappy Marriage of Law and Equity in Joint Return Liability, 108 Tax Notes 1307 (Sept. 12, 2005), also available on the Tax Analysts web site as Doc 2005-18027, 2005 TNT 176-31.  Here is part of the Introduction:

Today’s column discusses what happens when Congress attempts to smooth out the sharp corners of the tax code with notions of equity, but does so with an inadequate understanding of, or appreciation for, the problems of tax administration. The statute I discuss today, section 6015, is not the worst-written part of that dismal effort called the Internal Revenue Service Restructuring and Return Act of 1998 (RRA 98), but it is darned close. I shall explain why. More importantly, I shall offer some ideas on how to fix it, for it is not enough to criticize if one is not prepared to offer up ideas that can, in turn, get shot down by others.

In my last column [blogged here], I showed how Congress failed to give the Tax Court jurisdiction under 6015(e) to review IRS denials of section 6015(f) equitable relief in nondeficiency cases. Today’s column again concerns section 6015, but today I will examine the full interplay of its substantive provisions with tax procedure. In RRA 98, Congress increased the scope of equitable relief from joint and several liability. But the procedures it provided taxpayers who seek that relief are a conceptual and practical mess. The ironic result: In trying to cure old inequities, Congress created new ones. Because of RRA 98, substantive outcomes depend on choice of process. That is not good tax administration.

Part I of the article explains the history and theory of joint liability, because to understand the need for equity one needs to understand what corners of the law are too sharp and why. Part II explains how and why the concept of "innocent spouse" came into tax, and how that concept has remained the bedrock idea underlying all forms of joint liability relief enacted since 1971. Part III looks at the mess made by Congress in RRA 98 when it tried to cure the problem of access to court review, but improperly conflated the tax determination process with the tax collection process, creating gaps and traps for taxpayers, no matter how wary they may be. Part III also offers some ideas on what the taxwriters should or could do to fix the mess.