Canberra and the tragedy of the commons
Canberra, the capital of Australia, is known as the “garden city.” However, with increasing construction of residential areas and large areas of urban infill, the city is losing its greenery. Canberra has had policies in place that tried to limit the impact buildings could have on a property and allow plants to grow alongside them. Currently, the plot ratio is set at 50% for single dwelling homes, meaning that 50% of the plot must be left open to the air for plants and runoff. But there are many exceptions to the rules. For example, concrete courtyards and swimming pools cover large areas of property. And once a building is built, there is little that can be done and little incentive to correct the breaches. The people moving to these suburbs are presumably attracted by the greenery. But ironically, their McMansions actually decrease that very greenery one by one, an effect of the “tragedy of the commons.”
In order to combat this, professor Leo Dobes of the Australian National University, proposes a “leaf tax.” This tax would apply to homeowners whose homes exceeded the 50% plot ratio, and the less green left, the higher the tax would be. This way, the government would have a financial incentive for enforcing the plot ratios, and residents of the area would not lose the green that had attracted them to the area in the first place. Setting this “leaf tax” would make it possible to maximize the value of the greenery for everyone.