The article explores how the skill premium (pay gap between high-skilled and low-skilled workers) changes in economies with different levels of high-skilled labor. By considering costly investments in capital and research, as well as how different capital goods work together, the researchers found that in economies with more high-skilled workers, the skill premium increases when the relative number of high-skilled workers goes up. They also discovered that if investment costs or complementarities between capital goods increase, the number of high-skilled workers must also increase to maintain economic growth. In these economies, higher investment costs or complementarities also lead to a higher skill premium.