The quality and quantity of factors of production can be influenced by various economic and social factors. The quality of labor and capital can increase through better education, training, experience, and healthcare. The quantity of labor depends on population size, age structure, retirement age, and attitudes towards women working. It also depends on the number of hours worked, which is influenced by the length of the average work day and time lost to holidays and sickness. The quantity of capital depends on investment levels and tends to increase over time through spending on capital goods minus depreciation. While the amount of land does not change much, its quality can be increased through fertilizers and other methods.