Simplify the following text for a Grade 7 native English-speaking person.
Original: John Ledyard ( 2007 ) , Robert Lucas , Roger Myerson , Edward C. Prescott , James Quirk , Nancy Stokey and Neil Wallace are among those who have delivered the lecture since it was inaugurated in 1992 .
Simplified: John Ledyard ( 2007 ) , Robert Lucas , Roger Myerson , Edward C. Prescott , James Quirk , Nancy Stokey and Neil Wallace are some of the people who have given the lecture since it was thought to be important in 1992 .