A very good debate question!
Is happiness proportional to money?

But what exactly is 'M' here?
In terms of physics or mathematical formulae, you could call it a 'constant'
Something like what 'K' is in the below equation for spring constant :

½mV² = ½k*x²

In our case, 'M' would stand for more. Because when it comes to money, nobody gets enough, everybody wants more.
So, the equation would stand as below :

Happiness ∝ Money.
Now, if there is a constant 'M' thrown in, we can equate the 2 sides.
Happiness = M(money).

Now M could be 2 for a street urchin.
It would be 100 for a regular job guy.
It would be 1000 for a well-to-do business guy.
For John Abraham, it could be 10000, for SRK may be 1 million.
For Brad Pitt it would be 100 million, because he has Madame Jolie to take care of and a multi-coloured army too!

3 days back, I had a discussion with one of my friends where we were discussing exactly how important is money?
This is not a straight answer, alas!
His opinion was that when you just start earning, it is THE most important thing in the world for you.
Few years down the lane, when you have just enough... when I say that, I mean you have a decent amount in your bank account and you are still left with some disposable income, then you start thinking... Ok, this is not important enough.

This is exactly what happens to many of us including me.
Typically this state approaches you when you are close to 30.
You know yourself better and are more confident about what 'else' you need from life!
When you have something apart from fulfilling your basic needs, have a decent bank balance, you start thinking about the vagaries of life.

At this juncture, just stop and think,
Is money driving you to do things you would otherwise not have done?
For most, the answer would be yes.

I am just 27, but when I rewind my life, say 15 years, when I was in fifth grade, I find a culture shock, a lifestyle shock between what I was then and what I am now.

India as a country has changed so much in the last decade, that it is almost umimaginable to think that I had a acai-berry tree in my backyard!
I was never brought up in the countryside, all these were big Indian cities which had so much space just 2 decades back.
It was my dad's company provided quarter where we had a front yard, a back yard with a small kitchen garden.
On sundays I picked up 2 brushes, an old soft rag and shoe polish.
I took my dad's shoes, my school shoes and my mom's footwear occasionally and polished them!
The shine gave me happiness.
I played cricket till I dropped. That gave me happiness.
We did not have a car, but had a scooter which was pretty old.
My dad disposed it off and got a new scooter, I used to shine it up every weekend too like an energetic kid. That gave me happiness.
Probably everything that was not money in that age, gave me happiness.

I am sad when I compare that scene with today.
There are no big open yards in houses anymore. If there are, then you gotta be neo-rich to have them.
Plus even if you have them, you would probably employ someone to take care of the garden and the farm.
That because you don't have any time left for all this.
The kids in school these days, and this is a fact, are the most frequent visitors to pubs.
Hardly 15 something, armed with cash from their Arab-like cash rich dads, come in droves and smoke life away through a hukka nozzle!

Nothing is out of reach for the X-box generation.
Their happiness lasts till the time the credit limit on their dads' add-on cards last!

Sigh, its all about money and the constant 'M'.
The money will always be the same, but life has now been reduced to a constant journey of this 'M' from 2 to maybe 100 million.
So what if Jolie is taken, there will always be some local, maybe even more attractive versions available closer home!
Everyone dreams to be a Brad Pitt someday.

PS : I am a culprit of this spending-mela too, but maybe because I am already past being a teen, I spend a lot lesser than the empowered people today!
But, three cheers to the teens! They are what it takes to keep the recession away!