Should hawker centers impose a deposit to encourage customers to return their trays?

I asked this question in The Wisdom of the Crowd - Should hawker centers impose a deposit to encourage customers to return their trays?

50% of those who voted said that it is better to educate the customer, rather than impose a deposit. 23% said that it is better to let the work be done by people who need the job. 14% said that it is costly to set up the machine to handle the refund of the deposit. A total of 87% are against this move.

The remaining 13% said that it helps to improve productivity.

See the breakdown of the votes in
http://www.wisdomofthecrowd.sg/chart.aspx?ID=485