81977
Its principal investigators for the first four years of the partnership were Arthur Lupia and Jon Krosnick .
 Arthur Lupia, Jon Krosnick
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: media, plant, vehicle, astronomical object, time, disease, animal, location, person, organization, mythical figure, food, biology, geographical phenomenon, instrument, event 
Text: {0} 
Answer:
 Arthur Lupia, Jon Krosnick