In 2016, when the interest rate on 10-year German government bonds became negative, an article in the Wall Street Journal noted that the interest rate on 10-year bonds depended in part on investors’ expectations of future shortterm interest rates. The article also noted that “investors don't seem to have changed their perception of … [short-term] interest rates in the future.” If the article is correct, can the expectations theory explain why the interest rate on 10-year German government bonds declined? Can the liquidity premium theory? Briefly explain.