In almost all cases, the equity risk premiums based on long-term government bonds
tend to be smaller than those based on short-term government bonds.
Why? Isn’t it the other way around? Because the longer the term, the higher the premium?
Equity risk premium = expected market return - bond YTM
In most cases (upward sloping yield curve), long term gov bond YTM > short term gov bond YTM
but shouln’t the risk premium of a long term bond higher than the short tern bond?
Yes, the risk premium of a long term bond is higher than the risk premium of a short term bond, hence long term bonds have higher yield.
But your statement above is referring to equity risk premium (i.e. the risk premium of the equity market), and not the risk premium of a long term/short term bond