Why does an additional Variable get omitted in Fixed-Effects Estimation?

Hi, today I came across a strange problem. I found a panel data set online today (for the period 1980-1987). I first estimated a model with no fixed effects, but with time fixed effects (year dummies). As expected, one of the dummy variables was removed from the model (1980). I then used the fixed-effects estimator and observed something odd. Now, in addition to the 1980 dummy variable, the 1987 variable was also removed, as was the education variable. The education …

datascience effects fixed-effects