- 46 - tion with respect to the December 2, 1999 transaction that “The only rational explanation supported by the record is that the Petitioners were engaged in obtaining financing” with respect to lot 5. Petitioners do not dispute that if the Court were to reject, as the Court has, petitioners’ substantial authority argument, there would be a substantial understatement of tax within the meaning of section 6662(d)(1)(A) for their 1999 taxable year. We conclude that the burden of production under section 7491(c) imposed on respondent with respect to the accuracy-related pen- alty is satisfied. Petitioners not only advance petitioners’ substantial au- thority argument in support of their position that they are not liable for 1999 for the portion of the accuracy-related penalty that is attributable to their tax treatment of the December 2, 1999 transaction, they also maintain that they are not liable for such portion of the penalty because they had reasonable cause for, and acted in good faith in, not reporting that transaction as a sale in their 1999 return. In determining whether a taxpayer acted with reasonable cause and in good faith, generally the most important factor to consider “is the extent of the taxpayer’s effort to assess the taxpayer’s proper tax liability.” Sec. 1.6664-4(b)(1), Income Tax Regs. Petitioners made no effort to ascertain the proper taxPage: Previous 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 NextLast modified: November 10, 2007