You know that the effective tax rate still raises? For simplicity sake, consider that first 100K are taxed at 10% and next 100K at 20%. If you made 100K your e

You know that the effective tax rate still raises? For simplicity sake, consider that first 100K are taxed at 10% and next 100K at 20%. If you made 100K your effective tax had been 10% i.e. you owed 10K to the government, however if you made 200K, even though the first 100K is still taxed at the same rate, your effective rate is 15% because you now owe 30K out of 200K.