ðɪs mˈɑːdəl wʌzðə pɹɪkˈɜːsɚ tə ðə nˌiːoʊklˈæsɪkəl mˈɑːdəl ʌv ˌiːkənˈɑːmɪk ɡɹˈoʊθ, dˈɪfɚɹɪŋ mˈeɪnli ɪn ɪts ɹᵻstɹˈɪktɪv ɐsˈʌmpʃən ðætðə lˈiəntiːf pɹədˈʌkʃən fˈʌŋkʃən ɐplˈaɪd, wˌɪtʃ mˈɛnt ðɛɹ wʊd biː fˈɪkst pɹəpˈoːɹʃənz ʌv kˈæpɪɾəl ænd lˈeɪbɚɹ ɪn pɹədˈʌkʃən, nˌɑːt sˌʌbstɪtˈuːʃən bᵻtwˈiːn ðˌɛm.
This model was the precursor to the neoclassical model of economic growth, differing mainly in its restrictive assumption that the Leontief production function applied, which meant there would be fixed proportions of capital and labor in production, not substitution between them.