A face-to-face survey (N=388) was conducted in January 2019, in the Beni-Makada district of Tangier (Morocco). The district has the highest poverty rate (14 % versus 7 %), the lowest per capita green space (0.27m²), and houses more than 40% of its population, which makes it the densest and most disadvantaged neighborhood in Tangier.

During the 22^nd conference of parties (COP22) organized in 2016 in Morocco, the study area, attracted government and media attention partially because of the abundance of PSG. Efforts were made to further spread this practice in similar districts in Tangier and other cities through the organization of neighborhood competitions, and funding to NGOs.

There are approximatively 93.737 households in the district, 87% lives in individual patio houses called modern Moroccan houses. All PSG in the study area are present on neighborhood streets back to back with their owners’ houses therefore visible and accessible to all.

The used questionnaire was tested with focus groups and a certified translator fluent in Darija (Moroccan Arabic dialect) before being conducted. A sample size of a minimum of 384 (1 person per household) was calculated to achieve a significance level of α=0.05 and a 95% confidence level.

The interviews were conducted by four male university students, fluent in local dialect.

The study was approved by the ethics committee of the University of Tokyo. We obtained oral informed consent for adults or parental permission and oral assent for minors prior to each interview. Adulthood was defined according to its legal definition in Morocco (≥18 years).

Every participant receives extensive information about the study, its aims, anonymity of collected data and its exclusive use for scientific research. About 80% agreed to participate in the survey. All interviews were conducted in private. After four weeks, we obtained 388 valid questionnaires.