City Council Member Alan Gerson is suggesting that the congestion pricing fee be on a sliding, income-based scale, and that it not apply to either vehicles owned by non-profit organizations or those coming to Manhattan for medical care. Call it a Progressive Pigovian Tax, a reference to Professor Arthur Cecil Pigou who reckoned fees affect behavior. For your tax planning, we can imagine the following congestion pricing worksheet to assist drivers in calculating what the plan to reduce traffic and emissions will cost them, on a per-ride basis.

1. If you are a Democrat, subtract $10.

2. If you are a Republican, add $10.

3. If you are a Democrat-turned-Republican-turned-independent, add $1 billion.

4. If you are speeding and not wearing a seat belt, add $1 million.

5. If you are going to work on Wall Street, add $2.

6. If your vehicle belongs to a non-profit organization, subtract $2.

7. If the non-profit pays its chief executive more than $250,000 a year, add $1.

8. If you have an anti-war or anti-Bush bumper sticker, add $5, minus the cost of the bumper sticker, with a non-refundable credit for any campaign contributions made to the Barack Obama presidential campaign.

9. If you are driving a hybrid vehicle, subtract $3.

10. If it is a hybrid sport utility vehicle, add $4.

11. If you have E-Z Pass, deduct 10%.

12. If the battery is broken in the E-Z Pass transponder, deduct the cost of mailing the broken transponder back to New Jersey.

13. If you are coming into Manhattan for medical care, deduct the cost of your co-payment.

14. If you are uninsured, deduct $10, unless you are eligible for Medicaid and have failed to sign up, in which case, deduct $20.

15. If the medical care is elective cosmetic surgery, add $20, plus 10% of any fees you might be paid in the future by Eliot Spitzer.

16. If you are Governor Paterson, pay the fee with your campaign funds.

17. If you are driving to your rent-controlled apartment from your country home, add $30.

18. If you are driving a grocery truck, add $10.

19. If the groceries are organic and you are going to a farmer’s market, deduct $10.

20. If you are smoking in your car, add $10, plus any money you saved by buying the cigarettes from out of state. If you are both a smoker and an organic farmer who is speeding while driving a hybrid sport utility vehicle, return to line 1, and start over.

Come to think of it, maybe we’ll just take the subway — or walk. No wonder this congestion pricing is supposed to discourage driving. Once you start social engineering with the tax code, there’s no end to it.