The airlines need to make an unlikely move to boost performance (UAL, AAL, LUV, DAL)

Airlines must cut capacity to shore up profits and raise their stock prices, Morgan Stanley says.
Oil prices can — counter-intuitively — be a boost to margins, but will require other discipline from carriers.
All major US airlines have underperformed in 2018 thus far. 
Airline stocks have been a disappointment in recent months, and that isn’t likely to change until carriers cut capacity, Morgan Stanley warned clients this week.
Even as oil prices scream higher in 2018, whi