Hi, Here is my answer to question 3:

Suggest alternative measures other than banning the use of plastic bags.

I agree with Zhen Qiang's suggestion of putting more resources into R&D for biodegradable plastic bags. However, the development of these plastic bags are still in the early stage and the use of these bags are rather costly, so people tend to stick with the use of original plastic bags which are much more cheaper.

Thus, this are some suggestion of what we can do now as an alternative method:

1. The supermarkets can increase the number of BYOB day to once a week rather than once a month. This will help more people to remember which day to bring your own bag as it is required more offen. Thus, this will cut down on the use of plastic bags.
2. The supermarket can also train their staffs to put more items into a single plastic bag. Currently, the cashiers are only puting a few items in each bag and not filling them up to their maximun capacity. Thus, if they fill up each plastic bag with more items, they can cut down on the use of plastic bags.

The reduction in use of plastic bag will bring the MPB curve closer to the MSC curve, thus reducing the amount of negative externalities. For the meantime, before there is use of biodegradable plastic bags, we should all learn to reduce, reuse and recycle.

Kwok Cheung