arXiv subjects

Idris Adjerid

Publications and source records attributed to Idris Adjerid.

4 recordsLinked to original sources

arXiv2026

Breaking Bad Email Habits: Bounding the Impact of Simulated Phishing Campaigns

Simulated phishing campaigns are widely deployed, yet the behavioral data they produce is endogenous: because training is triggered by clicking, the employees receiving intervention have already demonstrated susceptibility. This endogeneity, combined with the difficulty of separating genuine habit formation from stable individual differences, means standard analyses can mischaracterize program effectiveness. In this Research Note, we develop a generalizable analytic framework addressing both biases simultaneously. We utilize marginal structural models (MSMs) to correct for the endogenous, click-triggered assignment of training, while integrating correlated random effects (CRE) to disentangle true state dependence from stable employee heterogeneity. Applying the MSM+CRE estimator to logs from 17 campaigns delivered to university staff (192,840 observations) reveals that analyses ignoring stable differences overstate the causal persistence of clicking; most repeat clicking reflects who employees are, not the effect of recent failures. This persistence is context-dependent, amplifying when successive campaigns share persuasion cues. Teachable-moment features also matter: emotion framing and explicit reporting pitches can largely eliminate persistence, while annotated-email cues modestly exacerbate it. Finally, employees engaging with the education page exhibit greater persistence than those dismissing it, consistent with an emboldening mechanism. We contribute methodologically by integrating MSMs and CRE into a portable framework for analyzing standard simulation logs, and practically by identifying specific design levers so organizations can better sequence and evaluate their phishing programs.

cs.CR↗

arXiv2023

Health Wearables, Gamification, and Healthful Activity

Health wearables in combination with gamification enable interventions that have the potential to increase physical activity -- a key determinant of health. However, the extant literature does not provide conclusive evidence on the benefits of gamification, and there are persistent concerns that competition-based gamification approaches will only benefit those who are highly active at the expense of those who are sedentary. We investigate the effect of Fitbit leaderboards on the number of steps taken by the user. Using a unique data set of Fitbit wearable users, some of whom participate in a leaderboard, we find that leaderboards lead to a 370 (3.5%) step increase in the users' daily physical activity. However, we find that the benefits of leaderboards are highly heterogeneous. Surprisingly, we find that those who were highly active prior to adoption are hurt by leaderboards and walk 630 fewer steps daily after adoption (a 5% relative decrease). In contrast, those who were sedentary prior to adoption benefited substantially from leaderboards and walked an additional 1,300 steps daily after adoption (a 15% relative increase). We find that these effects emerge because sedentary individuals benefit even when leaderboards are small and when they do not rank first on them. In contrast, highly active individuals are harmed by smaller leaderboards and only see benefit when they rank highly on large leaderboards. We posit that this unexpected divergence in effects could be due to the underappreciated potential of noncompetition dynamics (e.g., changes in expectations for exercise) to benefit sedentary users, but harm more active ones.

econ.GN↗

arXiv2019

Exploit Prediction Scoring System (EPSS)

Despite the massive investments in information security technologies and research over the past decades, the information security industry is still immature. In particular, the prioritization of remediation efforts within vulnerability management programs predominantly relies on a mixture of subjective expert opinion, severity scores, and incomplete data. Compounding the need for prioritization is the increase in the number of vulnerabilities the average enterprise has to remediate. This paper produces the first open, data-driven framework for assessing vulnerability threat, that is, the probability that a vulnerability will be exploited in the wild within the first twelve months after public disclosure. This scoring system has been designed to be simple enough to be implemented by practitioners without specialized tools or software, yet provides accurate estimates of exploitation. Moreover, the implementation is flexible enough that it can be updated as more, and better, data becomes available. We call this system the Exploit Prediction Scoring System, EPSS.

cs.CR↗

arXiv2018

Aggressive Economic Incentives and Physical Activity: The Role of Choice and Technology Decision Aids

Aggressive incentive schemes that allow individuals to impose economic punishment on themselves if they fail to meet health goals present a promising approach for encouraging healthier behavior. However, the element of choice inherent in these schemes introduces concerns that only non-representative sectors of the population will select aggressive incentives, leaving value on the table for those who don't opt in. In a field experiment conducted over a 29 week period on individuals wearing Fitbit activity trackers, we find modest and short lived increases in physical activity for those provided the choice of aggressive incentives. In contrast, we find significant and persistent increases for those assigned (oftentimes against their stated preference) to the same aggressive incentives. The modest benefits for those provided a choice seems to emerge because those who benefited most from the aggressive incentives were the least likely to choose them, and it was those who did not need them who opted in. These results are confirmed in a follow up lab experiment. We also find that benefits to individuals assigned to aggressive incentives were pronounced if they also updated their step target in the Fitbit mobile application to match the new activity goal we provided them. Our findings have important implications for incentive based interventions to improve health behavior. For firms and policy makers, our results suggest that one effective strategy for encouraging sustained healthy behavior combines exposure to aggressive incentive schemes to jolt individuals out of their comfort zones with technology decision aids that help individuals sustain this behavior after incentives end.

econ.GN↗