This article estimates long-term output using two distinct theoretical approaches. The first is the demand-led growth approach. In this approach, two long-term output models are estimated: that of Shaikh and Moudud (2004), with a modification to capture demand-driven technical change in the Kaldorian sense (Kaldor, 1957); and that of Thirlwall (1979), according to which the theoretical long-term growth rates of the economy are determined by export growth rates. The second approach is the neoclassical approach of Solow (1956) and Swan (1956). In this approach, long-term growth is limited by supply factors (the factors of production capital and labor).