In a tournament, when the BB goes up and they start to charge an ante, how should you adapt your style? Should you make your game looser or be more aggressive?
In a structure with no antes, you will only lose 1.5BB per orbit if you fold all of your hands. This structure allows you to play really tight, since there is time to wait for premium hands.
But when the antes kick in, you are putting in more money per orbit. There is no time to sit and wait for premiums. You have to play more aggressive. Also, like Dr.drfbaglll pointed out, there is more dead money in the pot. So being aggresives and winning pre-flop is a big win.
This makes sense when we look at the 2 extreme sides of this. When there are both no antes and no blinds, correct strategy would be to only open aces. And when a big blind is as big as your stack, you have to play nearly 100% of your hands.
To conclude: the lower the blinds and antes relative to the effective stack size the tighter you should play.
Note: just because you should does not mean everybody does it. When people play too tight or too aggressive, you should still always punish them.
It is more you need to loosen up when antes kick in. You need to play more hands as an orbit cost you more.
Go with whatever your multiple of the BB was. With ante maybe add 1 BB.
If you have the stack you can afford to play tight and bully at times.
If you are short stacked you just need to play relative to the BB.
In the money or close more aggressive is not necessary the way to go but there are times you are going to need to gamble.