Giovanna d’Adda, chaired professor at the University of Milan (U Milan), and Associate editor at the European Economic Review, visited NCID to give a seminar entitled “How many nudges are enough? Multiple nudges, resources' conservation and customer engagement”. The speaker explained that “Behavioral nudges are more and more common so people are usually more exposed to several different nudges, but research hasn’t told us much about the cumulative effect of multiple nudges and what happens to behaviors that are not directly targeted by the nudge. This is what this research is about”.

In this paper, she runs an experiment with a utility company in Italy sending its costumers social information nudges on the water usage, and these customers receive other records for electricity and gas. “What we find is that the report reduces water and electricity consumption, so is not just water what it intends to reduce but also electricity. But this effect it’s observable only for costumers for whom the water report is the first. So they don’t receive any other report”.

d’Adda also confirms that these indirect effects are reducing the effectiveness of additional notches and impacts are stronger for the first nudge due to spillover effects.