が増えれば

if … increases

→ が
phrase Rare #36,285
if … increases が marks what is increasing. 増えれば is the conditional form of 増える; the phrase can also mean “if there are more ….”
JA: 友達が増えれば、毎日がもっと楽しくなる。
EN: If you make more friends, every day becomes more fun.

収入が増えれば増えるほど、消費もいっそう多くなる。

The more your income increases, the more you spend.

知人が増えれば増えるほど、それだけ会う時間が少なくなる。

The more acquaintances you have, the less time you have to meet with them.

釣りに使える時間が増えれば、食事に使う金よりずっと速く稼げる。

If I had more time to fish, I could earn money much faster than I spend it on food.

遊びが増えれば勉強する時間が減ることになるだろう。

If you spend more time having fun, you'll probably have less time to study.