A prize purchase

A colleague who required his students to purchase a copy of his (excellent) textbook found an inspired way to solve the conflict of interest problem highlighted in the story "Now apply in writing to go on reading list" (March 17) - he staged a lottery in his Friday morning lecture each week.

The lottery prize amounted to that week's fraction of royalties generated by the book sales to his 200 students.

As you might guess, attendance at that Friday lecture always approached 100 per cent.

W. Lee Hansen
Professor emeritus
Department of economics
University of Wisconsin, US