Research Seminars Series

Learning principles of individual and collective behavior from data

Have you ever wondered how are colonies of ants able to efficiently search for food, birds or fish collectively defend themselves against predators by forming flocks or schools, and why crowds of people behave like a fluid? Recent advances in automated tracking technology resulted in high-resolution recordings of individual trajectories and behavior of groups, often complemented by identification of stereotypical behaviors. But the main hurdle still remains to be data analysis and inference of informative models. I will talk about a class of probabilistic models, which is general enough to apply to a broad range of systems, incorporating individual and collective behavior, spatial and temporal dependence, discrete and continuous variables, deterministic and stochastic components and internal cognitive or behavioral state dependence. Our approach has two desirable features: (1) the maximum likelihood inference is tractably solvable by gradient descent, (2) model selection can be used to adjust model complexity to data. Multiple toy/real examples will be shown during the talk.​

Gulags, Crime, and Violence: Origins and Consequences of the Russian Mafia

This paper studies the origins and consequences of the Russian Mafia (vory-v-zakone). Using a web scraping method, I obtained a unique dataset that contains detailed biographies of more than 5,000 mafia leaders operating in 15 countries of the (former) Soviet Union at some point between 1916 and 2018. Using this data, I first show that Russian Mafia originated in the Gulag - Soviet system of forced labor camps which housed around 18 million prisoners between 1920s-1950s. Second, I document that the distance to the nearest camp is a strong negative predictor of mafia presence in Russia's communities in the mid-1990s. Finally, using an instrumental variable approach which exploits the spatial distribution of the gulags, I examine the effects of mafia presence in mid-1990s on local crime and violence. In particular, I show that the communities with mafia presence experienced a dramatic rise in crime driven by turf wars which erupted among rival clans around 1993 and lingered on until the late 1990s. This is suggested by a sharp increase in attacks against members of Russia's economic elite in places under mafia control.  Further heterogeneity analysis reveals that mafia presence led to a spike in violence against businessmen, fellow criminals, as well as law enforcement officers and judges, while the attacks against politicians remained unaffected.

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Rank incentives and social learning: evidence from a randomized controlled trial

In a 1-year randomized controlled trial involving thousands of university stu- dents, we provide real-time private feedback on relative performance in a semester-long on- line assignment. Within this setup, our experimental design cleanly identifies the behavioral response to rank incentives (i.e., the incentives stemming from an inherent preference for high rank). We find that rank incentives not only boost performance in the related assignment, but also increase the average grade across all course exams taken over the semester by 0.21 standard deviations. These beneficial effects remain sizeable across all quantiles and extend beyond the time of the intervention. The mechanism behind these findings involves social learning: rank incentives make students engage more in peer interactions, which lead them to perform significantly better across the board. Finally, we explore the virtues of real-time feedback by analyzing a number of alternative variations in the way it is provided.

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Delegation Based on Cheap Talk

We study a real effort environment, where a delegator has to decide if and to whom to delegate a task. Delegating to a person who is better at the task increases welfare. Potential delegatees send cheap-talk messages about their past performance before the delegator decides. We experimentally test the theoretical prediction that information transmission cannot occur. In our experiment, we vary the message space available to the delegatees and compare the information transmitted and the level of efficiency. Depending on the treatment, the sender can either submit a number indicating how many tasks she solved previously, an interval in which the number of tasks falls, or a free text message. We observe that messages contain information in all treatments. Interestingly, information transmission occurs only in the treatments where messages are intervals or free text but not if messages are exact. The highest efficiency is obtained in the free-text treatment, as delegators are able to extract information contained in the different styles of messages sent by subjects with different abilities.

The role of diagnostic ability in markets for expert services

In credence goods markets, experts have better information about the appropriate quality of treatment than their customers. Experts may exploit their informational advantage by defrauding customers. Market institutions have been shown theoretically to be effective in mitigating fraudulent expert behavior. We analyze whether this positive result carries over when experts are heterogeneous in their diagnostic abilities. We find that efficient market outcomes are always possible. However, inefficient equilibria can also exist. When such inefficient equilibria are played, a larger share of high-ability experts may lead to more inefficiencies relative to the efficient equilibria.

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Setbacks and learnings from doing experimental research: different contexts, multiple results?

Over the last years, the use of experimental research has received an increasing attention from Management academics and journal editors. While experimental research is popular among social psychologists (actually my background) it is still rare in the field of International Human Resource Management. The objective of this seminar is not to explain how to design an experimental research, but instead, present my own experience of using experimental designs to answer a few common questions in the management and business fields, such as: (1) Does the academic performance (GPA) and the participation in extracurricular activities (ECAs) affect the perceived employability of business graduates? (2) Does the effect of GPA and ECAs vary with the characteristics of the respondents and the cultural context? (3) Does a facultative internship affect the perceived employability of marketing graduates? What about the effect of an international versus a domestic facultative internship? (4) Does the use of a facial piercing influence the perceptions of interpersonal attraction, confidence and job suitability of hospitality receptionists? Starting from my first published paper (Pinto & Ramalheira, 2017) employing an experimental design, I then illustrate how this method was applied more broadly to examine the perceived employability of business graduates in other cultural contexts (e.g. China, Brazil, Italy) and to advance research in other fields, such as hospitality management, higher education and leadership. The seminar ends with a discussion of the challenges and learnings from employing (quasi) experimental designs.

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Reporting Peer Misbehavior: Experimental Evidence on the Effect of Monetary Incentives on Morally Controversial Behavior

Reporting a peer’s wrongdoing to an authority is a morally controversial decision: re-porting will likely result in a punishment for the peer (and harming others is unethical), but the punitive action might prevent further harm to the victims of the misconduct (which justifies reporting on a moral ground). A policymaker might want to encourage the solution of this moral dilemma in the direction of reporting, through financial incentives. Yet, material incentives sometimes backfire, especially in domains involving moral concerns. Using a field experiment with employees of the Ministry of Education in Afghanistan who are asked to confidentially report their colleagues’ absence, I show that reporting is lower among participants who are offered a monetary reward for their reports. This is the case, however, only for participants who expect their reports to be consequential (making their choice morally-charged). Among employees who are told instead that their reports are inconsequential and won't result in any penalty for their peers (making the choice more morally-neutral), incentives do not backfire.

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Where or Whom to Contract? An Empirical Study of Political Spillovers in Public Procurement

Abstract: OECD and other international organizations have been very keen in recommending principles and institutional safeguards to curb corruption and to enhance transparency and integrity in public procurement. Despite the fact that Portugal is being considered a good example of e-procurement policies and practices among European countries, this is a very sensitive issue.
Based on the the literature that provides evidence of a politicized administration of public procure- ment contracts, but limited to a specific municipality, this paper extends the analysis of political effects to other municipalities. Specifically, it asks if there is a relation between the political parties in power in a given municipality and the frequency of contracts awarded to a given firm?
Our results show that for political reasons private firms are more likely to win a contract in a given municipality if they have already won contracts in other municipalities led by the same political party. We rely on a dataset (’base.gov’) with information on all bids by private firms and all contracts awarded by the 308 Portuguese municipalities in the period between 2008 and 2017. This includes three electoral cycles and more than 250,000. The empirical results - the political proximity - is robust to a number controls, including geographic proximity. This result has political and public governance implications.

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Migration, Health, and Well-Being

Foreign-born individuals come with different health needs and different level of vulnerability. In the public debate today, immigration is often viewed as a threat to the access and the quality of health care services. The health needs of immigrants and refugees pose new challenges to health care systems. We discuss the main findings of the effects of immigration on demand and supply of health care in host countries. Moreover, immigrant inflows could have large effects on labour markets which can in turn affect natives’ health and their demand for health care. Understanding the health trajectories of immigrants are paramount to provide a correct assessment of the costs and benefits of migration.

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Wishful thinking about mood effect

There is increasing acceptance of the role played by mood in decision-making. However, the evidence of mood effect in the field, as proxied by external factors such as weather and weekday, is limited. Using two large datasets containing all car inspections in Sweden and England during 2016 and 2017, we study whether inspectors are more lenient on days when their mood is predicted to be good, and if car owners exploit this mood effect by submitting lower quality cars to be inspected on these days. Different sources of good mood are studied: Fridays, last working days before public holidays, paydays, sunny days, and days following major sports results, in a decreasing order of the car owner’s ability to plan for inspection, and hence the likelihood of selection bias. We find limited evidence to support the existence of mood effect in this domain, despite survey results showing belief to the contrary. In Sweden, failure rate is in fact higher on Fridays and last days before holidays, suggesting that the selection effect is stronger than any mood effect.

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