"oil = 100*(log(realoilq) - log(L.realoilq))"
"Define realoilq as quarterly average of realoilm"
"Define realoilm = MCOILWTICO / PCEPI (monthly)"
"Based on FRED mnemonics MCOILWTICO and PCEPI (monthly)"
"gdp = 400*(log(GDPC1) - log(L.GDPC1))"
"Based on FRED mnemonic GDPC1"
"Retrieved 2013-01-19"
"Economic data from St. Louis Fed's FRED database."