$2.00 Gas! Studying the Effects of a Gas Tax Moratorium

There are surprisingly few estimates of the effect of sales taxes on retail prices, especially at the firm level. Further, along both sides of a state border, a change in one state%u2019s sales tax can shed light on the nature of competition, as a subset of firms effectively experiences a change in its marginal cost. This paper considers the suspension, and subsequent reinstatement, of the 5% gasoline sales tax in Illinois and Indiana following a temporary price spike in the spring of 2000. Earlier laws set the timing of the reinstatements, providing plausibly exogenous changes in the tax rates. Using a unique dataset of daily, gas station-level data, retail gas prices are found to drop by 3% following the suspension, and increase by 4% following the reinstatements. After linking the stations to driving distance data, some evidence suggests that the tax increases are associated with higher prices up to an hour%u2019s drive into neighboring states.

Evaluating the Effectiveness of Child Safety Seats and Seat Belts in Protecting Children from Injury

Young children are required to use child safety seats, and the age threshold at which children can legally graduate to seat belts has steadily increased. This paper tests the relative effectiveness of child safety seats, lap-and-shoulder seat belts, and lap belts in preventing injuries among motor vehicle passengers aged 2-6. We analyze three large, representative samples of crashes reported to police, as well as linked hospital data. We find no apparent difference in the two most serious injury categories for children in child safety seats versus lap-and-shoulder belts. Child safety seats provide a statistically significant 25% reduction in the least serious injury category. Lap belts are somewhat less effective than the two other types of restraints, but far superior to riding unrestrained.

Causal effects of foster care: An instrumental-variables approach

This paper describes the use of instrumental-variables (IV) to estimate causal effects of foster care on long- and short-term outcomes. This estimation strategy provides a tool to evaluate what are known as "natural experiments": settings that mimic randomization usually associated with a controlled trial. The proposed natural experiment involves the effective randomization of investigators to child-protection cases. The results suggest that foster care placement increases like likelihood of delinquency and emergency healthcare episodes. Care must be taken when interpreting IV estimates. The results apply to cases that are part of the natural experiment-"marginal cases" where the investigators may disagree about the placement recommendation. Keywords: Foster care; Instrumental variables; Causal effectsNational Science Foundation (U.S.) (Grant SES-0518757

How effective is lifeline banking in assisting the 'unbanked'?

Many consumers who lack checking accounts are paying relatively high costs to access the nation's payments system. Legislation aimed at opening the system to these unbanked individuals has centered on requiring commercial banks to offer low-cost "lifeline" accounts. But will cost savings alone motivate these consumers to access the payments system through banks?Checking accounts ; Banks and banking - Service charges ; Poverty

Juvenile Incarceration, Human Capital, and Future Crime: Evidence from Randomly Assigned Judges

Over 130,000 juveniles are detained in the United States each year with 70,000 in detention on any given day, yet little is known about whether such a penalty deters future crime or interrupts social and human capital formation in a way that increases the likelihood of later criminal behavior. This article uses the incarceration tendency of randomly assigned judges as an instrumental variable to estimate causal effects of juvenile incarceration on high school completion and adult recidivism. Estimates based on over 35,000 juvenile offenders over a 10-year period from a large urban county in the United States suggest that juvenile incarceration results in substantially lower high school completion rates and higher adult incarceration rates, including for violent crimes. In an attempt to understand the large effects, we found that incarceration for this population could be very disruptive, greatly reducing the likelihood of ever returning to school and, for those who do return, significantly increasing the likelihood of being classified as having an emotional or behavioral disorder

Child Protection and Adult Crime: Using Investigator Assignment to Estimate Causal Effects of Foster Care

Nearly 20% of young prison inmates spent part of their youth in foster care - the placement of abused or neglected children with substitute families. Little is known whether foster care placement reduces or increases the likelihood of criminal behavior. This paper uses the placement frequency of child protection investigators as an instrument to identify causal effects of foster care placement on adult arrest, conviction, and imprisonment rates. A unique dataset that links child abuse investigation data to criminal justice data in Illinois allows a comparison of adult crime outcomes across individuals who were investigated for abuse or neglect as children. Families are effectively randomized to child protection investigators through a rotational assignment process, and child characteristics are similar across investigators. Nevertheless, investigator placement frequencies are predictive of subsequent foster care placement, and the results suggest that school-aged children who are on the margin of placement have lower adult arrest rates when they remain at home.

Returns to Local-Area Health Care Spending: Using Health Shocks to Patients Far From Home

Health care spending varies widely across markets, yet there is little evidence that higher spending translates into better health outcomes, possibly due to endogeneity bias. The main innovation in this paper compares outcomes of patients who are exposed to different health care systems that were not designed for them: patients who are far from home when a health emergency strikes. The universe of emergencies in Florida from 1996-2003 is considered, and visitors who become ill in high-spending areas have significantly lower mortality rates compared to similar visitors in lower-spending areas. The results are robust across different types of patients and within groups of destinations that appear to be close demand substitutes.

Edgeworth cycles revisited

Some gasoline markets exhibit remarkable price cycles, where price spikes are followed by a series of small price declines: a pattern consistent with a model of Edgeworth cycles described by Maskin and Tirole. We extend the model and empirically test its predictions with a new dataset of daily station-level prices in 115 US cities. Consistent with the theory, and often in contrast with previous empirical work, we find the least and most concentrated markets are much less likely to exhibit cycling behavior both within and across cities; areas with more independent convenience-store gas stations are also more likely to cycle

After Midnight: A Regression Discontinuity Design in Length of Postpartum Hospital Stays

Patients who receive more hospital treatment tend to have worse underlying health, confounding estimates of the returns to such care. This paper compares the costs and benefits of extending the length of hospital stay following delivery using a discontinuity in stay length for infants born close to midnight. Third-party reimbursement rules in California entitle newborns to a minimum number of hospital "days," counted as the number of midnights in care. A newborn delivered at 12:05 a.m. will have an extra night of reimbursable care compared to an infant born minutes earlier. We use a dataset of all California births from 1991-2002, including nearly 100,000 births within 20 minutes of midnight, and find that children born just prior to midnight have significantly shorter lengths of stay than those born just after midnight, despite similar observable characteristics. Furthermore, a law change in 1997 entitled newborns to a minimum of 2 days in care. The midnight discontinuity can therefore be used to consider two distinct treatments: increasing stay length from one to two nights (prior to the law change) and from two to three nights (following the law change). On both margins, we find no effect of stay length on readmissions or mortality for either the infant or the mother, and the estimates are precise. The results suggest that for uncomplicated births, longer hospitals stays incur substantial costs without apparent health benefits.

Intelligent assistance in scientific data preparation

Scientific data preparation is the process of extracting usable scientific data from raw instrument data. This task involves noise detection (and subsequent noise classification and flagging or removal), extracting data from compressed forms, and construction of derivative or aggregate data (e.g. spectral densities or running averages). A software system called PIPE provides intelligent assistance to users developing scientific data preparation plans using a programming language called Master Plumber. PIPE provides this assistance capability by using a process description to create a dependency model of the scientific data preparation plan. This dependency model can then be used to verify syntactic and semantic constraints on processing steps to perform limited plan validation. PIPE also provides capabilities for using this model to assist in debugging faulty data preparation plans. In this case, the process model is used to focus the developer's attention upon those processing steps and data elements that were used in computing the faulty output values. Finally, the dependency model of a plan can be used to perform plan optimization and run time estimation. These capabilities allow scientists to spend less time developing data preparation procedures and more time on scientific analysis tasks