I found a penny tonight and got to thinking.
I did some testing, and the amount of time it takes to reach down, pick up a penny, and be on your merry way is approximately 3 seconds.
Now, if you consider those three seconds as work done to earn that penny, and multiply it to an hourly wage; for those three seconds you're working at a rate of 12 dollars an hour:
(1 cent/3 seconds)(3600 seconds in an hour)=12
This is, of course, disregarding any sense of accomplishment, security, or well-being gained from the aquisition of a lucky, or shiny new penny. We're talking pure economics here.
I don't have a statistic but I'd be willing to bet that well over half of this country's work force works for less than a 12 dollar an hour wage. That's frightening when you break it down and realize that every three seconds they're getting a penny tossed their way.
Currenly, I don't earn 12 dollars an hour so I could consider any penny I find to be a well earned (and highly lucrative for my three second's time) income.
If you make more than 12 dollars an hour at your job or, more importantly, if you value your time at more than 12 dollars an hour despite the corner the capitalist machine has you pushed into, then picking up a penny is a waste of your precious time, mathematically speaking.
Furthermore, I've developed an equation that will determine the value of a coin (or small amount of coins, say no more than three) that is worth reaching for, depending on what hourly wage you're willing to work for:
let x be your desired hourly wage
let y be the value of the coins you've stumbled upon
3(x/3600)=y
If you value your time at minimum wage in the state of New York (currently 6.75), you're rolling in money town if you find any coins worth at least a little more than half a cent.
If you value your time at 100 dollars an hour then you'd do well to pick up any find of 8 cents or more.
Because of this observation I've decided that it's very hard to argue against the economic soundness of picking up any change the average person finds on the sidewalk. You'd have to be making over 300 dollars an hour to scoff at the thought of picking up a quarter.