what econometric model fits for a research regarding a country's debts, interest

[MariaKatrina]

rate, money supply, etc? what econometric model or any statistical treatment that fits for a research regarding a country's debts, interest rate, money supply, tax rate, i wanna see the effects or relationship between each of the variables. i am going to use this for my methods of analysis.
Granger Causality is only in my mind right now
Thanks for helping