Bounding the Bias of Tree-Like Sampling in IP Topologies

It is widely believed that the Internet's AS-graph degree distribution obeys a power-law form. Most of the evidence showing the power-law distribution is based on BGP data. However, it was recently argued that since BGP collects data in a tree-like fashion, it only produces a sample of the degree distribution, and this sample may be biased. This argument was backed by simulation data and mathematical analysis, which demonstrated that under certain conditions a tree sampling procedure can produce an artificail power-law in the degree distribution. Thus, although the observed degree distribution of the AS-graph follows a power-law, this phenomenon may be an artifact of the sampling process. In this work we provide some evidence to the contrary. We show, by analysis and simulation, that when the underlying graph degree distribution obeys a power-law with an exponent larger than 2, a tree-like sampling process produces a negligible bias in the sampled degree distribution. Furthermore, recent data collected from the DIMES project, which is not based on BGP sampling, indicates that the underlying AS-graph indeed obeys a power-law degree distribution with an exponent larger than 2. By combining this empirical data with our analysis, we conclude that the bias in the degree distribution calculated from BGP data is negligible.Comment: 12 pages, 1 figur

Racial Disparity in Marijuana Policing in New Orleans

In national research, self-reported marijuana use is similar across races, but in New Orleans, black people are disproportionately arrested for marijuana offenses, including simple possession. While some states have legalized marijuana in recent years, the consequences for marijuana possession in Louisiana remain severe—under state law, repeated convictions for simple possession are punishable by multi-year prison sentences. This report illuminates through quantitative analysis the persistent racial disparities in marijuana policing from 2010 to 2015, and discusses the impacts of statutory and policy reforms the city has implemented to date. Through these findings, the report aims to guide state and local policymakers toward further improvements to lessen the harm even seemingly minor police encounters inflict on black communities, and inspire other jurisdictions to examine their own practices

Past Due: Examining the Costs and Consequences of Charging for Justice in New Orleans

In 2015, government agencies in New Orleans collected $4.5 million in the form of bail, fines and fees from people involved in the criminal justice system and, by extension, from their families. Another$4.7 million was transferred from the pockets of residents to for-profit bail bond agents. These costs have become the subject of considerable public attention. Because many "users" of the system have very low incomes or none at all, there is growing concern that charging for justice amounts to criminalizing poverty, especially when people who can't pay become further entangled in the justice system. In 2015, the city spent $6.4 million to incarcerate people who couldn't pay bail or conviction fines and fees. By focusing on bail decisions and fines and fees assessed at conviction, Past Due, and its accompanying technical report, reveals the costs and other consequences of a system that tries to extract money from low-income people and then jails them when they can't pay