Norwich City, Derby County and Wigan Athletic have parted company with Alex Neil, Steve McClaren and Warren Joyce respectively in the past week.
McCarthy was appointed in November 2012, and his side are currently seven points above the relegation zone.
"We've been competitive every season up until this one," he said.
"We haven't spent Aston Villa money. We haven't spent Norwich money. We haven't spent vast sums of money."
McCarthy added to BBC Radio Suffolk that the fact he is still in post confirmed that "for four years I've done a really good job here" - but that "this year it has been tough".
Last season the Tractor Boys finished seventh in the table, five points adrift of the play-off places.
Defender Christophe Berra has said that the current table suggests the team are in a relegation battle.
"Seven points isn't that big a gap. Two or three wins would ease it, but it is getting tough," he said.
Berra suggested the club's predicament could be down to a lack of spending.
"We've not made the most investments," he said. "Teams in and around us have maybe done a little bit more."
Midfielder Luke Hyam, meanwhile, has been ruled out for another six weeks after rupturing ankle ligaments in training.
Hyam, 25, has yet to play for the first team this season after previously undergoing surgery on a damaged nerve in his leg.
Ipswich Town's Mick McCarthy says he has not joined the string of managers sacked by Championship clubs because he has "done a really good job".