The First Annual Zero Graffiti International Conference was held in San Francisco last week. Hundreds of police officers, public works officials, “graffiti” consultants, and industry reps from 52 cities gathered as the industry that has grown up around abatement announced that it had made $17 billion in profit in the United State alone. ┬áDespite the massive expenditure, no study has been undertaken to measure the effectiveness of simple abatement on vandalism recidivism. San Francisco alone spends $20 – 30 million…