Hi Gordon, I believe in the scenario you describe an employee paying a class D stamp would receive 3/4 of 50k multiplied by the actuarial reduction factor - I think its around 62% for age 50 if normal pension age is 60. So in that case it would be around 23250. For an employee paying a class A stamp it is more complicated because the pension is coordinated. I believe in this scenario that no supplementary pension is payable in advance of normal pension age, say 60 in this case. There is a formula used to work out the occupational part of the pension due in this circumstance and it is (3*COAP)*(Years Worked)/200 + (Final Salary - 3*COAP)*(Years Worked)/80. So in the case you describe, an employee paying the class A stamp would get a pension at 50 of (35880)*30/200 + (100000-35880)*30/80 = 5382 + 24045 = 29427. This would then be subject to the actuarial reduction factor of 62% to give a pension at 50 of 18244.
So you can see that there is some disparity between what an employee paying class D versus class A receives on actuarially reduced retirement. For the class A employee, provided they are not employed, they can then apply for a supplementary pension from age 60. This would be the difference between what a class D employee would receive at 60 if they hadn't opted for early retirement and what the class A employee would receive at 60, again assuming they hadn't opted for early retirement. I make this to be (37500 - 29427) = 8073. So I think (!) the class A employee will receive a total pension from age 60 of 18244 + 8073 = 26317. So even though the class A employee gets less pension between 50 and 60 in this case, they do better than the class D employee from 60-66/67 and actually when the class A employee reaches state pension age, I believe they will get the full COAP, losing the supplementary pension at that point, so their entire pension would be 18244 + 11960 = 30204. So, at state pension age, I believe the class A employee in this case would receive another "boost" to their overall pension, leaving them a good bit better off than their class D equivalent at that stage, who continues to receive 23250.
I believe these calculations are correct but please let me know if there is any discrepancies. Another contributor pointed out in the past that if the average age at death is taken into account, then overall the class D pension payout and class A pension payout match up very closely.