The subject of unconventional monetary policy needs to be expanded

Recently. I found a thesis on unconventional monetary policy during the Global Financial Crisis, written by Zhang (2013). The thesis was well written, covering several crucial points including the impact of quantitative easing, forward guidance, and quantitative easing on household deleveraging.

This thesis was written in 2013 when the global economy was still recovering from the crisis. Since then, there were more unconventional policies introduced to complement the existing policies. These were:

1. Negative interest rates on reserves, implemented by the European Central Bank in response to the European Sovereign Debt Crisis, and the Bank of Japan in response to the strengthening Japanese Yen.
2. Yield curve control, which was implemented by the Bank of Japan (unsurprisingly) and recently by the Reserve Bank of Australia in response to the COVID-19 outbreak.

The end goal of these mentioned policies is similar to forward guidance and QE, which is to influence term premium and real interest rates. But not enough work on the theoretical approach on these subject, and the effectiveness of these policies, especially on yield curve control. Therefore, the subject of unconventional monetary policy needs to be expanded by focusing on those two policies I just mentioned above.