Capturing the Laws of (Data) Nature

Model fitting is at the core of many scientific and industrial applications. These models encode a wealth of domain knowledge, something a database decidedly lacks. Except for simple cases, databases could not hope to achieve a deeper understanding of the hidden relationships in the data yet. We propose to harvest the statistical models that users fit to the stored data as part of their analysis and use them to advance physical data storage and approximate query answering to unprecedented levels of performance. We motivate our approach with an astronomical use case and discuss its pote

Do Physicians Respond to Liability Standards?

In this paper, we explore the sensitivity in the clinical decisions of physicians to the standards of care expected of them under the law, drawing on the abandonment by states over time of rules holding physicians to standards determined by local customs and the contemporaneous adoption of national-standard rules. Using data on broad rates of surgical interventions at the county-by-year level from the Area Resource File, we find that local surgery rates converge towards national surgery rates upon the adoption of national-standard rules. Moreover, we find that these effects are more pronounced among rural counties

Modeling the scaling properties of human mobility

While the fat tailed jump size and the waiting time distributions characterizing individual human trajectories strongly suggest the relevance of the continuous time random walk (CTRW) models of human mobility, no one seriously believes that human traces are truly random. Given the importance of human mobility, from epidemic modeling to traffic prediction and urban planning, we need quantitative models that can account for the statistical characteristics of individual human trajectories. Here we use empirical data on human mobility, captured by mobile phone traces, to show that the predictions of the CTRW models are in systematic conflict with the empirical results. We introduce two principles that govern human trajectories, allowing us to build a statistically self-consistent microscopic model for individual human mobility. The model not only accounts for the empirically observed scaling laws but also allows us to analytically predict most of the pertinent scaling exponents

The Effect of Statutory Rape Laws on Teen Birth Rates

Policymakers have often been explicit in expanding statutory rape laws to reduce teenage pregnancies and live births by teenage mothers, often with the goal of reducing associated welfare outlays. In this paper, we explore whether expansions in such laws are indeed associated with reductions in teen birth rates. In order to codify statutory-rape-law expansions, we use a national micro-level sample of sexual encounters to simulate the degree to which such encounters generally implicate the relevant laws. By codifying statutory-rape laws in terms of their potential reach into sexual encounters, as opposed to using crude binary treatment variables, this simulation approach facilitates the use of multi-state difference-in-difference designs in the face of highly heterogeneous legal structures. Our results suggest that live birth rates for teenage mothers fall by roughly 4.5 percent (or 0.1 percentage points) upon a 1 standard-deviation increase in the share of sexual activity among a given age group that triggers a felony for the elder party to the encounter. This response, however, is highly heterogeneous across ages and weakens notably in the case of the older teen years. Furthermore, we do not find strong results suggesting a further decline in birth rates upon increases in punishment severities

The Deterrent Effect of Death Penalty Eligibility: Evidence from the Adoption of Child Murder Eligibility Factors

We draw on within-state variations in the reach of capital punishment statutes between 1977 and 2004 to identify the deterrent effects associated with capital eligibility. Focusing on the most prevalent eligibility expansion, we estimate that the adoption of a child murder factor is associated with an approximately 20% reduction in the homicide rate of youth victims. Eligibility expansions may enhance deterrence by (1) paving the way for more executions and (2) providing prosecutors with greater leverage to secure enhanced non-capital sentences. While executions themselves are rare, this latter channel is likely to be triggered fairly regularly, providing a reasonable basis for a general deterrent response

Capturing Individual Harms

The aggregated lifestyles and behaviors of individuals impose significant environmental harms yet remain largely unregulated. A growing literature recognizes the environmental significance of individual behaviors, critiques the failure of environmental law and policy to capture harms traceable to individual behaviors, and suggests and evaluates strategies for capturing individual harms going forward. This Article contributes to the existing literature by approaching the problem of environmentally significant individual harms through the lens of environmental federalism. Using climate change and individual greenhouse gas (“GHG”) emissions as an exemplar, the Article illustrates how local information, local governments, and local implementation can enhance policies designed to capture individual environmental harms. Local information and community-level implementation may enhance norm management efforts designed to influence GHG-emitting behaviors by (1) allowing for the identification of concrete behaviors that are feasible to target through norm management in a given community; (2) informing the design and content of norm campaigns, including the selection of the abstract norm that will form the basis of the appeal for specific behavioral change; and (3) facilitating effective implementation strategies. This framework supports a preference for local action expressed, but to date largely unexamined, in the broader norm management literature. Additionally, the Article argues that obstacles to using mandates to influence GHG-emitting behaviors may be less formidable when mandates are developed and enforced locally. Local development and enforcement of mandates can reduce intrusion objections because (1) individuals are accustomed to local control over day-to-day behaviors; (2) familiarity with local attitudes and practices enables the design of mandates that avoid intrusion objections; and (3) local governments are in a better position to structure time, place, and manner restrictions that channel behavior while preserving some individual choice. Local design and enforcement of mandates may also minimize the key enforcement challenges of expense, numerosity, and (in)visibility