Dr. MacDonald's research on urban green spaces was highlighed in Scientific American magazine thanks to the findings from his recent study in Philadelphia. MacDonald and his co-authors randomly sampled 541 vacant lots and randomly assigned them to intervention (cleanup) or non-intervention (control) categories. Police reports and randomly-sampled resident surveys over the next three years found that reducing blight significantly reduced all crimes, gun assaults, and burglaries. The study was published in Proceedings of the National Academy of Sciences of the United States of America (PNAS) and is titled Citywide cluster randomized trial to restore blighted vacant land and its effects on violence, crime, and fear. For more from Scientific American, click here. To access the full study at PNAS, click here.