clear all set more off freduse GS1 TB3MS tsmktim time, start(1934m1) tsset time rename TB3MS t3month label variable t3 "3-Month Treasury" rename GS1 t1year label variable t1year "One-Year Treasury" tsline t3 graph rename plot1 dfuller t3, lags(12) reg d.t3 L.t3 L(1/12).d.t3 gen spread = t1year - t3 tsline spread graph rename plot2 dfuller spread, lags(12) * Real GDP clear freduse GDPC1 tsmktim time, start(1947q1) tsset time rename GDPC1 rgdp generate ln_rgdp = ln(rgdp) dfuller ln_rgdp, trend lags(2)