Hi, new R user here. I have a panel data of 30 countries spanning 60 years and I wish to explore the impact of political institutions on economic outcomes. To this end, I would like to implement a GLS with random effects and time dummies. My problem starts with the next step. As the panel covers 60 years, I would like to set a time horizon of 15 years to have four panelS for each country. What is the most efficient way to implement this?
Thank you in advance for any suggestions!