19677
Deeper analyses of this topic were taken up in industrial organization economics by crossover economics / strategic-management scholars such as Harold Demsetz and Michael Porter .
 Harold Demsetz, Michael Porter
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:
 Harold Demsetz, Michael Porter