Another is credit costs -- in other words, the devaluation costs of impaired assets. Sales growth for borrowing firms is expected to be weak without nominal GDP growth, and their loans could very well turn into nonperforming ones. Following the introduction of QQE, the nominal GDP growth rate, which had been negative since the global financial crisis, has turned positive.
Looking back, Japan's nominal GDP, which had posted more or less negative growth since 1998, resumed positive growth from 2004 as the economy enjoyed the effects of QE introduced in 2001.