1817
David Ricardo in his early works analysed the pricing of exhaustible resources , where he argued that the price of a mineral resource should increase over time .
 person: David Ricardo
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
 Entities: David Ricardo 
Answer:
 person: David Ricardo