Linear Regression or Panel Regression

Hello

I just read a paper and would like to try to replicate it. However, I don't exactly understand whether the author of the paper is doing a linear regression or a panel regression. His regression equation looks like this

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with y_it denoting subjective inequality indices for individual i in year t. The regressor of main interest is East_it, a dummy variable denoting current residency in East Germany. The regression also includes a series of control variables and survey-year fixed effects, denoted by x_it and λ_t, respectively.

I know that he has a dataset for 3 years (1987, 1992 and 1999) in which he performs the regression, but he does not mention whether he is performing a linear regression or a panel regression, he only mentions, and I quote: "I run a series of simple regression models".
What do you think the author does in his paper a panel regression or a linear regression? I'm confused because I'm not quite sure if you can do a linear regression with a dataset over 3 years with a dummy.

Thank you so much for your help.