Nuno Jose Lopes


As a PhD candidate of Marketing, I do research on collective decision. Specifically, I spent the last years investigating the decision processes used by groups of two customers when there are many alternatives available (choice overload) and also how stressful decisions affect their emotions. Studying groups is fascinating and important as human beings are social animals “condemned” to live, work, and consume with each other. My work has been presented in several international conferences.

Before joining IESE, I worked in sales, consulting, marketing management, and retail, both in Portugal and Spain. Not surprisingly, consumer behaviour is one of my passions, and when traveling I never miss an opportunity to see how people shop around the world.


• Lopes, N. J., Reutskaja, E., Capizzani, M., & Iyengar, S. S. “When Selecting from Many Gets Easier: The Moderating Effect of Collective Choice”*. Manuscript submitted to the Journal of Consumer Research (October 2016).
* This paper was previously presented with the title “Absinthe + Brandy = Champagne: How Dyads Moderate Choice Overload”.

Choosing from a large set of alternatives can negatively affect the decision, a phenomenon known as choice overload. Our paper is the first to investigate this phenomenon in a group setting. Four studies demonstrate that the negative effects arising from a large number of alternatives (measured by decision process difficulty, buying rate, and sampling rate) significantly diminish when decisions are made collectively by two people. This has to do with the fact that, in order to maintain the harmony within the dyad, its members frequently prefer to forego his or her own favorite alternative and focus their discussion on those alternatives liked by both dyad members. This process of preferences’ convergence into a common ground (Schelling point) reduces the consideration set of the dyad in comparison to individuals, and offers an explanation for the diminishment of choice overload in a collective setting.

• Lopes, N. J. & Reutskaja, E. “Happy Together: The Emotional Positive Effect of Shopping in Group”. Data analysis in process. Target journal: Journal of Marketing Research.

Choosing from a large assortment requires the individual decision maker to trade-off between several alternatives, which typically arises several negative emotions. Yet, as people enjoy sharing activities with their peers, this negativity can be reversed if the decision is made by a group of two people. On a laboratory study where the six basic emotions (i.e., happiness, surprise, sadness, anger, fear, disgust) were measured using automatic facial recognition, we show that whereas individuals’ decision process was dominated by a variety of negative emotions such as anger and sadness, dyads, on the contrary highly enjoyed the process of selecting one movie from a large choice set.

Nuno Jose Lopes

PhD Candidate

Academic Area


Dissertation Director

Prof. Elena Reutskaja


• MBA (ESADE, Spain)
• BA Business Administration (Universidade Católica Portuguesa, Portugal)

Research Interests

Consumer Behavior, Group Decision Making, Emotions, Choice Overload, Sensory Marketing, Construction of the Consideration Set.

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