hiː hɐz ˈɔːlsoʊ wˈɜːkt wɪð lˈiːəm ɡɹˈeɪəm ɔnðə θˈiəɹi ʌv hɛdˈɑːnɪk ˌædæptˈeɪʃən ɪnðə tˈuː θˈaʊzənd tˈɛn dʒˈɜːnəl ʌv ˌiːkənˈɑːmɪk bᵻhˈeɪvjɚ ænd ˌɔːɹɡɐnᵻzˈeɪʃən; ɐ kˈiː aɪdˈiə ɪn ðɛɹ pˈeɪpɚɹ ɪz ðæt hjˈuːmənz hæv ɐ pˈuːl ʌv sˈaɪkɪk ɹᵻsˈoːɹsᵻz kˈɔːld baɪ ðɪ ˈɔːθɚz hɛdˈɑːnɪk kˈæpɪɾəl.
He has also worked with Liam Graham on the theory of hedonic adaptation (in the 2010 Journal of Economic Behavior and Organization); a key idea in their paper is that humans have a pool of psychic resources called by the authors 'hedonic capital'.