Hello together

I have a regression which includes 2 survey years, namely 1999 and 2009. I am not sure whether I should use a panel regression (plm) or just a linear model (lm) with dummy variable for the respective year (1999 or 2009).

Can anyone give me a recommendation?

I have tried the following:

```
lm1 <- lm(giniA~ region+dummy_1999+age+status,data=fors)
#or should i use plm
plm1 <- plm(giniA~ region+age+status, data=fors, index = c("year"),model = "pooling")
```

Moreover, if I should make a panel regression, which model (pooling, fd, within,..) would be most suitable for a regression with two survey years?

Many thanks!