Thomas Ahn

Geospatial Patterns in Human Papillomavirus Vaccination Uptake: Evidence from Uninsured and Publicly Insured Children in North Carolina

Background: Human papillomavirus (HPV) vaccination coverage is far below the national objective set by Healthy People 2020. This paper explores spatial patterns in HPV vaccination uptake. Methods: Secondary data for publicly funded HPV vaccinations among age-eligible children from 2008 through 2013 from the North Carolina Immunization Registry (NCIR) were used in 2014 in an ecological analysis at the ZIP code tabulation area (ZCTA) level. We tested for spatial autocorrelation in unadjusted HPV vaccination rates using choropleth maps and Morans I. We estimated nonspatial and spatial negative binomial models with spatially correlated random effects adjusted for demographic, economic, and healthcare variables drawn from the 2010 U.S. Census Bureau, 2008–2012 American Community Survey, 2010 ZIP Business Patterns, and the 2012–2013 Area Resource File. Results: The NCIR revealed areas of especially low rates in publicly funded HPV vaccinations among uninsured and means-tested, publicly insured children. For boys, but not girls, ZCTAs tended to have HPV vaccination rates that were similar to their neighbors. This result was partially explained by included ZCTA characteristics, but not wholly. Conclusions: To the extent that the geospatial clustering of vaccination rates is due to causal influences from one ZCTA to another (e.g., through information networks), targeting interventions to increase HPV vaccination in one area could also lead to increases in neighboring areas. Impact: Spatial targeting of HPV vaccination, especially in clusters of low vaccination areas, could be an effective strategy to reduce the spread of HPV and related cancers. Cancer Epidemiol Biomarkers Prev; 24(3); 595–602. ©2015 AACR.

The short-run impacts of Connecticut’s paid sick leave legislation

In 2012, Connecticut became the first state to enact paid sick leave legislation. Using a difference-in-differences framework, we find the law had modest but negative effects on the labour market, particularly on the likelihood of working in the past week.

Paid Sick Leave and Absenteeism: The First Evidence from the U.S.

Using a balanced sample of workers from the NHIS, we estimate of the impact of paid sick leave (PSL) insurance on absenteeism in the United States. PSL increases absenteeism by 1.2 days per year, a large effect given the typical benefit duration. Consistent with moral hazard, the effects are concentrated in moderate sick days, not severe ones. In addition, we merge the NHIS with Google Flu Trends. Severe influenza outbreaks lead workers to exhaust sick days, consequently leading to a replacement rate of zero for additional absences. Consistent with a lower replacement rate, worker absenteeism is reduced on the margin.

A Note On Bubbles, Worthless Assets, And The Curious Case Of General Motors

Since the company declared bankruptcy in June 2009, shares of General Motors stock (now known as Motors Liquidation Company) have continued to trade at a high volume while maintaining a market capitalization near

The Impact of No Child Left Behind's Accountability Sanctions on School Performance: Regression Discontinuity Evidence from North Carolina

300 million through most of 2010. Anecdotal evidence strongly suggests that both rational speculators and uninformed investors (often mistaking Motors Liquidation for the new, reorganized GM) have purchased the stock. We develop a theoretical asset-pricing model that includes both types of agents. We present two major results. First, the most frequent state is one where a small fraction of rational agents ensure that the share price behaves as if all agents are rational. A second state exists where all rational agents exit and the share price is inflated. Second, fitting the model to Motors Liquidation, we find evidence of irrational asset pricing for this firm. We find little evidence of similar behavior in the share prices of the thirty stocks that compose the Dow Jones Industrial Average.