What is the relationship between 'Janet Yellen' and 'economist' in the context of the input sentence.
Options: position held, location of formation, subsidiary, chief executive officer

Kevin Lamarque | Reuters Janet Yellen "A weaker-than-expected rise in consumer prices at the start of Q3 further fuels the dovish argument for the Fed to remain on the sideline, delaying liftoff beyond the September FOMC meeting," Lindsey Piegza, chief economist at Stifel Fixed Income, said in a note.
position held