No matter how they are characterized, dinners, trips and other perks provided by textbook publishers to school officials in any decision-making capacity immediately raise legal, if not ethical, questions. Sanseido Co. in Japan and Pearson Co. in the United States highlight the fine line between legitimate business practices and shady dealings.

When Sanseido recently apologized for entertaining school principals and providing them with "editing fees" in the hope of influencing the textbook selection process of local governments, it hoped to erase the stain on its reputation. That's because in Japan publishers are not permitted to provide outsiders with a preview of any textbook subject to screening by local boards of education. It was violation of the vetting process that eventually led to Sanseido's exposure. Ever since the company started publishing elementary school textbooks in 2009, it had arranged annual editorial meetings to which school principals were invited. Their hotel and dining expenses were fully covered, and they received compensation cloaked as editing fees.

But school principals were equally culpable. They can't make a plausible case that they didn't know why they were given special treatment. Only the most naive person would believe their version when it was quite evident that a quid pro quo existed.