The decrease of raw material and process costs for the production of plastic materials has led to an inflation of this class of material. This is especially true for daily consumer goods (packaging).
Therefore, a plastic bottle is inherently worth less than a glass bottle. Since its production is less energy demanding if the fact that it relies on fossil raw materials is omitted. Hence, plastic bottles if sold in bulk volumes can create much more revenue. This is exactly what has happened since polypropylene, polyethylene and polycarbonate have been commercialized in 1957.
Since then, the way we consume materials has changed dramatically in a truly unsustainable way which is not the consumer’s fault, but the fault of research and development that was so fascinated about the properties of these synthetic materials so that a comprehensive analysis of materials usage and disposal was not done.
A way out would be to increase the value of a reusable packaging glass container by a certain amount each time it is reused. This means the older the container the more it is worth if you bring it back for refilling. In Germany you get a fixed amount of money back if you return bottles. It is 0.08 EUR for glass bottles that you return to the grocery whereas for a plastic bottle you get 0.25 EUR. Hereby, the value of something that has originally a lower value is artificially increased in order to create an incentive to return it. Which is fair enough.
However, it makes us think we get out more if we buy a plastic bottle and return it compared to a glass bottle. This may be called value inversion.
It has been shown that the plastic waste lying around in public could be reduced by this incentive. However, our perception of materials values has been changed which is a huge problem. Since we all know that a major fraction of the plastics returned ends up in landfill. As these materials are not suitable to be reused as many times as glass bottles for the simple reason that they are much more abrasive than glass bottles. The only way out is to avoid plastic bottles wherever possible! This will need a new incentive!