“…The first contributions, both of them for the case of the US economy, were those of Bohn (1998) and Canzoneri, Cumby and Diba (2001), who pioneered the two main approaches employed to test for the FTPL, namely, the so-called backward-looking and forwardlooking approaches, respectively. So, Bohn (1998) obtains, by means of econometric techniques, a positive response of the primary surplus-to-GDP ratio to the (lagged) debtto-GDP ratio.…”