ɐ ɹᵻlˈeɪɾᵻd bˌʌt dˈɪfɹənt ɐpɹˈoʊtʃ, wˌɛɹ pˈiːpəl ɑːɹ ˈæskt hˌaʊ ðeɪ fˈiːl ɐbˌaʊt ɐ vɚɹˈaɪəɾi ʌv ˈɪŋkʌm lˈɛvəlz, wʌz baɪ bɜːnˈɑːɹd vˈæn pɹˈɑːɡ nˈaɪntiːnhˈʌndɹɪd sˈɛvənti wˈʌn ænd hɪz lˈeɪdən skˈuːl.
A related but different approach, where people are asked how they feel about a variety of income levels, was by Bernard van Praag (1971) and his Leyden school.