A selection bias approach in the circular economy context: The case of organic municipal solid waste in Italy

Organic waste is often indicative of the amount of food waste, and it primarily reflects the consumption habits of households. As underlined by the applicable principles of the Circular Economy (CE), prevention is always the first choice when dealing with waste but evaluating the prevention framework without considering the application of waste separation policies appears to be a complex task. Considering Italian municipal waste management, the implementation of separation policies has been delayed in several provinces. It is difficult to assess the effectiveness of prevention policies established by international and national authorities in this context. The lack of organic waste separation is registered as a missing value in datasets: such instances are often non-random. The research objective of this work is to assess whether economic activity affects organic waste generation and, once the selection bias has been investigated, try to assess the overall implications. Initial findings corroborate the Environmental Kuznets Curve Hypothesis under biased and unbiased estimations. The tipping point is relatively lower when the inverse Mills Ratio is considered, which is positive. Hence, an increase of the expected economic activity requirement could result in a cost that municipalities incur when delaying the enforcement of separation policies. The missing information undermines the potential feedback from practitioners and other stakeholders capable of steering expectations: the unobserved flows have to reach a certain level before being collected.