- The document discusses economic growth models including the Solow and Romer models. - The Solow model views output as a function of capital and is subject to diminishing returns, while the Romer model incorporates ideas and innovations which can experience increasing returns. - In the Solow model, steady state is reached when savings/investment equals depreciation, but growth can occur by raising the savings rate or productivity. The Romer model sees ideas as multiplying rather than just adding to growth.