Lastly, let me explain capital input. Why is capital input not increasing? This is similar to asking why investment is not increasing in line with profits.
Reasons for this include low growth expectations, the self-fulfilling nature of growth expectations, and sluggish growth in domestic business fixed investment caused by the strong appetite for overseas  For examples of black firms, see Konno Haruki, Burakku kigyō, Nihon o kuitsubusu yōkai (Tokyo: Bunshun Shinsho, 2012).