Call Me When You Get Home”: New Technologies, and Safety in Public Spaces

Safety in public spaces is a global concern that can negatively impact individuals’ well-being, cause them to avoid certain activities, and lead to additional expenditures to feel secure. In this study, we document the prevalence of safety concerns and experiences of harassment among university students in the UK. We evaluate an innovative technology aimed at improving public safety, examine its uptake, and explore willingness to pay for safety—particularly with attention to gender differences.

Safety in public spaces is a global concern that can negatively impact subjective well-being, cause individuals to forgo valuable activities, and lead them to incur additional costs to feel secure. In this study, we begin by documenting the incidence of the problem—highlighting the prevalence of harassment and safety concerns among university students in the UK.

We then evaluate an innovative technological intervention aimed at enhancing public safety, particularly in relation to harassment. Using a randomized controlled trial, we assign students to different versions of a novel mobile safety app. This experimental design, combined with rich administrative and survey data, allows us to estimate the causal effects of the intervention on key outcomes, including perceived safety, crime experiences, mental health (anxiety and PTSD), commuting behavior, time use, and educational outcomes.

We also examine willingness to pay for safety and conduct heterogeneity analysis by gender. In addition, we study selection into participation and the determinants of app take-up.

The project follows a randomized experimental design involving a sample of university students (both women and men). To maximize participation, most students are invited to complete a baseline survey during class time and are compensated both for completing the survey and for correctly answering selected questions. At the end of the baseline, students are offered additional incentives—randomized into high and low incentive groups—to download the VIOLA RESEARCH app, a mobile safety app that initially went viral in Italy.

Students who choose to download the app and agree to location tracking are further randomized into two groups: a Control Group, which receives access to the app with geolocation functionality only, and a Treatment Group, which also gains access to a video-call feature enabling 24/7 connection with trained supporters. Users sign-up in the app using a unique "tester ID." An endline survey is then conducted two/three months later, either via email or through the app. Survey responses are merged with administrative data to support comprehensive analysis.

2025-03-24

2026-01-22

1. Safety perceptions (at night alone) - survey data
2. Mobility (time, mode of transport, itineraries, in group/alone) - survey data + admin data
3. (Anticipated) Anxiety walking at night - survey data

We will correct for multiple hypothesis testing when necessary. For each family of outcomes, we will construct summary indices and also analyze individual outcomes separately.

1. Safety perceptions (at night while alone) are measured using survey data, specifically six situational questions rated on a 1–5 Likert scale, as well as the question, “When is the last time you were willing to walk alone at night?” We will construct a general index of safety perception, along with separate indices for: (i) safety while walking or using public transport, and (ii) safety across specific types of situations. For analysis, we will transform the Likert-scale responses into binary (dummy) variables.

2. The data here comes from different sources (self-reported data, admin data from the university, and data from the app). Here as well we will construct first a general index of mobility at night, and then analyze each group and outcome separately.

3. Anticipated anxiety (Likert 1-5) and Intensity (1-10) will be reported in their original scale version and dummy version.

1. Harassment experiences (past two months) - survey data
2. PTSD (PC-PTSD-5) and GAD-7 - survey data
3. Academic engagement, performance, and choices - admin data
4. Trust in different types of interventions/institutions - survey data
5. Beliefs about harassment — We measure participants’ beliefs regarding their probability of harassment and incidence.

1. Harassment experiences are measured by asking respondents whether they experienced specific events in the past two months, in order to avoid relying on potentially varying interpretations of the term “sexual harassment.” At baseline, we also include a randomized subsample to which we apply hard garbling techniques, allowing us to estimate average misreporting. We construct a dummy variable indicating whether any incident occurred in the past two months, as well as separate dummies for each specific type of incident. We also report the frequency of sexual harassment.
2. PSTD questions are asked only to people that reported having experienced at least one form of sexual harassment (scale 0-5). GAD-7 we report the dummy for minimal anxiety.
3. Educational outcomes are only for students for which we have admin data:
Class attendance (% of scheduled classes)
Exam performance (0-100 scale)
Engagement (on a 1-4 scale, as reported by class teachers)

The project follows a randomized experimental design involving a sample of university students (both men and women) in the UK. To maximize participation, most of the students are invited to complete a baseline survey during class time and are compensated both for completing the survey and for correctly answering selected questions. At the end of the baseline, students are offered further incentives to download the VIOLA RESEARCH app—a new mobile safety app that became viral in Italy. At the end of the baseline survey, students who consent to location tracking are randomized into two groups. Users sign-up in the app using a unique "tester ID." An endline survey is then conducted two/three months later, either via email or through the app. Survey responses are merged with administrative data to support comprehensive analysis.

The project follows a randomized experimental design involving a sample of university students (both men and women). To maximize participation, most of the students are invited to complete a baseline survey during class time and are compensated both for completing the survey and for correctly answering selected questions. At the end of the baseline, students are offered further incentives to download the VIOLA RESEARCH app—a mobile safety app that became viral in Italy. The incentive amount is randomized into a high and a low group.

Students who choose to download the app (and consent to location tracking) are then randomized into two groups: a Control Group, which receives access to the app with geolocation functionality only, and a Treatment Group, which receives access to both geolocation and a video-call feature (users have the option to activate a 24/7 video call with trained supporters). An endline survey is conducted two/three months later, either via email or directly through the app. Administrative data are merged with survey data to enrich the analysis.

We anticipate the need to conduct multiple rounds due to power considerations. As a result, the experimental design may be slightly adjusted, and the sample could be expanded to include Italian students. If so, we will update this pre-registration plan accordingly.

Randomization done by the computer directly on Qualtrics

Individual

No

N/A

We aim to survey approximately 10,000 students, although the final number may vary depending on the availability and cooperation of professors and university administration. We anticipate conducting multiple rounds of data collection, subject to funding availability, and will update this pre-registration plan accordingly. Eligible participants are students who (i) are at least 18 years old and (ii) provide informed consent to participate in the study. As of now, we have surveyed 1,111 students.

50% control group, 50% treatment group.