premise: ISTANBUL, March 17 (Reuters) - Turkey’s central bank said on Tuesday it would maintain tight monetary policy until there was a significant improvement in the outlook for inflation. In a statement accompanying its decision to leave key interest rates unchanged, the bank said favourable developments in trade and the moderate course of consumer loans would help Turkey’s current account balance to improve.
hypothesis: The outlook for inflation is a key factor in their decisions. 
reason: They said they were going to continue their tight monetary policy until the outlook for inflation improved. Thus that was a big part of their decisions when making the policy.