Research Projects

This research tests hypotheses that the interests of corporations, businesses, and large property owners influence patterns of policing, gentrification, and urban economic development. Real estate holds great political and economic power in the functioning of New York City. This project investigates the actors involved in the growth of the real estate market, those responsible for its implementation, and the ways its regulation occurs and falls short. I focus on types of ownership and neighborhood characteristics to study where landlords site development projects and the ways development projects and residents are policed (or not) by the state. In particular, this project aims to address the research questions:

1) What is the relationship between real estate development and policing patterns, specifically for order maintenance offenses, in the area? Does order maintenance policing increase in areas experiencing real estate development? How does this relationship vary for different areas of the city and different types of developers, such as corporate, government, and individual?

2) How does the permit process for new building developments unfold across space and over time in NYC? How is it "policed" and resisted? How is the process related to patterns of ownership, wealth concentration, gentrification, and eviction?

3) How does surveillance technology alter the regulation of urban housing and the policing of public space?

I combine large-scale administrative data on policing, particularly low-level order maintenance arrests, with real estate development permit filings, a novel metric of physical investment, in New York City. I find that increases in real estate development are positively associated with increased rates of disorder policing. This relationship persists in models with year fixed effects but not two-way fixed effects, indicating strong cross-sectional variation. Segmenting the city by income and race shows that this relationship is strongest not only in areas at risk of gentrification, but also in wealthier and whiter tracts, suggesting that development-directed order maintenance policing functions to protect increasing capital investment in areas that are already heavily invested. Whereas most research on policing focuses on poor and Black neighborhoods, this analysis provides complementary insight into how policing functions to maintain control in invested areas of the city. I further find that this relationship is driven by corporate-owned permits, suggesting that large-scale developers may have a unique relationship to policing patterns. 

In a second paper, I take a deeper look at other forms of "policing" in urban development and the ways landlords skirt regulations. I leverage large-scale administrative data on permit filings over the past 25 years in New York City to predict how and where permit filings expand into broader development projects. I use web-scraped housing complaints in combination with eviction filings, rent stabilization, ownership patterns, and demographic data. I then explore spatial analyses of how these patterns vary across the city in relation to measures of gentrification, locations of street-level surveillance tools, and buildings involved in a pilot tenant harassment prevention program. Findings provide direction on ways to enhance tenant protection policies and how development patterns impact the composition of the city.

Papers

Pullen-Blasnik, Hannah. Under Review. “To Protect and Serve Capital: Policing, Real Estate Development, and the Regulation of Wealthy Spaces in New York City.” 

Pullen-Blasnik, Hannah. Work in Progress. "Development Permitting, Regulation, and Landlord Power in NYC."

Carceral algorithms encompass the broad category of algorithmic, automated, and data-driven practices employed in the criminal legal system. This work shows how algorithmic and predictive technologies facilitate processes of criminalization and spatial regulation, with a particular focus on the human decision-makers behind these tools. 

Drawing on a combination of in-depth interviews, legal document analysis, and quantitative data, this project explores how algorithms challenge decision-making processes in policing, prosecution, and how expertise gets wielded. My recent paper examines these expertise tensions in probabilistic DNA profiling. While often introduced as part of an “objectivity campaign” that positions the technology as more impartial, objective, and scientific, this work shows that in practice these tools still rely on human decision-makers in ways that can create tensions in established regulatory structures, reinforce or obfuscate existing biases, and expand the scope of carceral systems. 

Work in progress compares how these dynamics unfold across international contexts and different technological interventions such as facial recognition technology, risk assessment instruments, and predictive policing. Preliminary results show that facial recognition's use, similar to DNA analysis, involves discretionary decision-making to "fix" algorithmic outputs, but its legitimacy in the courtroom is far more tenuous and leads to different structures of expertise and authority.

I am also working on policy reports on carceral AI and an annual review article on technologies of criminalization.

This project is supported by the Trust Collaboratory at Columbia University.

Papers

Pullen-Blasnik, Hannah, Gil Eyal, and Amy Weissenbach. 2024. "'Is your accuser me, or is it the software?' Ambiguity and contested expertise in probabilistic DNA profiling." Social Studies of Science.

Pruss, Dasha, Hannah Pullen-Blasnik, Shakeer Rahman, et al. Forthcoming. “Prediction and Punishment: Critical Report on Carceral AI.” Berkman Klein Center. 

Rollins, Oliver, Julien Larregue, and Hannah Pullen-Blasnik. Under Review. “Technologies of Criminalization.” Annual Review of Law and Social Science.

Pullen-Blasnik, Hannah. Work in Progress. "Expertise and Legal Contestation in Carceral Technologies: Comparisons in Probabilistic DNA Profiling and Facial Recognition Technology."

The Black Lives Matter protests following George Floyd’s murder during the summer of 2020 demonstrated an unprecedented scale of mobilization against police violence. This project explores how the rapid and severe economic recession created by the COVID-19 pandemic related to protest participation. 

We combine paycheck employment data with crowdsourced protest attendance data for 491 commuting zones in the United States. We find that elevated rates of sudden job loss in an area during the early months of the pandemic were positively and significantly associated with greater rates of local BLM protest attendance. This relationship is not observed for other protests during the same period, indicating a specific relationship between police brutality and economic shock. This paper won the 2023 ASA Collective Behavior and Social Movement's Mayer N. Zald Distinguished Contribution to Scholarship Student Paper Award and is currently under review.

Other projects have cleaned and explored policing data on changes to 311 and 911 calls during the height of Covid-19 lockdowns and conducted a large-scale community interview project with business owners about their relationships to local policing.

Papers

Habr, Katy* and Hannah Pullen-Blasnik*. Under Review. “A Convergence of Crises: Sudden Employment Loss and Black Lives Matter Protest Attendance During the Covid-19 Pandemic.”
    * co-first authorship

Astoria Public Safety Research Team (including Hannah Pullen-Blasnik*). Forthcoming. "Small Businesses and Relationships to Policing and Public Safety.” Offices of Assemblymember Zohran Mamdani and Councilmember Tiffany Cabán.

Solitary confinement is an extreme form of imprisonment that isolates individuals in highly restricted cells. This project aims to understand the scope and impact of such harsh conditions and their long-term effects on social and economic outcomes.

My work estimates the population prevalence of solitary confinement. We find that 11% of all black men in Pennsylvania, born 1986 to 1989, were incarcerated in solitary confinement by age 32. Reflecting large racial disparities, the population prevalence is only 3.4% for Latinos and 1.4% for white men. About 9% of black men in the state cohort were held in solitary for more than 15 consecutive days, violating the United Nations standards for minimum treatment of incarcerated people. Findings suggest that harsh conditions of U.S. incarceration have population-level effects on black men’s well-being. 

Work in progress examines the impact of risk assessment instruments used at prison intake on incarceration, punishment, and parole decisions.

This work is part of the Pennsylvania Solitary Study at the Columbia Justice Lab. 

Papers

Pullen-Blasnik, Hannah, Jessica T. Simes, and Bruce Western. 2021. “The Population Prevalence of Solitary Confinement.” Science Advances.
    - Press coverage in New Scientist, Daily Mail, & The Appeal

Pullen-Blasnik, Hannah. Work in Progress. “Predictive Accuracy or Causal Impact? Carceral Risk Score Assignment, Impacts on Reentry, and Tools for Resistance.”

How do states, neighborhoods, networks, and technology affect people’s ability to avoid debt and improve their economic well-being? What can big data techniques illustrate about patterns of navigating the urban environment, and how do those patterns reflect (or not) qualitative experiences of space and place? 

This study uses large-scale proprietary point-of-interest and mobility data from SafeGraph and Advan to understand the nature, precursors, and consequences of racial differences in access to services, and particularly financial institutions. I use distributed computing clusters to build data pipelines to process data tracking the movement of individuals between census blocks and public amenities for over 200,000 financial institutions across the US. Combining this data with travel paths extracted from routing APIs, we hypothesize that urban areas show racially-biased barriers in accessing financial resources, encouraging predatory lending in poor and Black neighborhoods. 

This work is part of the Data and Racial Inequality Project at Incite at Columbia University. 

Papers

Work in Progress. "Access vs. Use: Urban Spatial Inequality in Financial Institutions." With Taylor Alarcon and Mario Small.