On my website, I have seen a significantly decline in revenue from adsense in recent weeks. My amount of clicks is the same as prior months, but the payout is way less. Does anyone know or can direct me to how google determines the payout per click?
It depends on the number of advertisers bidding for website with content like yours. The more they believe/see that your site attracts the kind of customer they are looking for, the more they will put money on it (and the higher the payout per click).