Surge pricing on a service platform under spatial spillovers: evidence from Uber

Ride-sharing platforms employ surge pricing to match anticipated capacity spillover with demand. We develop an optimization model to characterize the relationship between surge price and spillover. We test predicted relationships using a spatial panel model on a dataset from Ubers operation. Results reveal that Ubers pricing accounts for both capacity and price spillover. There is a debate in the management community on the ecacy of labor welfare mechanisms associated with shared capacity. We conduct counterfactual analysis to provide guidance in regards to the debate, for managing congestion, while accounting for consumer and labor welfare through this online platform.First author draf

When Fair Classification Meets Noisy Protected Attributes

The operationalization of algorithmic fairness comes with several practical challenges, not the least of which is the availability or reliability of protected attributes in datasets. In real-world contexts, practical and legal impediments may prevent the collection and use of demographic data, making it difficult to ensure algorithmic fairness. While initial fairness algorithms did not consider these limitations, recent proposals aim to achieve algorithmic fairness in classification by incorporating noisiness in protected attributes or not using protected attributes at all. To the best of our knowledge, this is the first head-to-head study of fair classification algorithms to compare attribute-reliant, noise-tolerant and attribute-blind algorithms along the dual axes of predictivity and fairness. We evaluated these algorithms via case studies on four real-world datasets and synthetic perturbations. Our study reveals that attribute-blind and noise-tolerant fair classifiers can potentially achieve similar level of performance as attribute-reliant algorithms, even when protected attributes are noisy. However, implementing them in practice requires careful nuance. Our study provides insights into the practical implications of using fair classification algorithms in scenarios where protected attributes are noisy or partially available.Comment: Accepted at the 6th AAAI/ACM Conference on Artificial Intelligence, Ethics and Society (AIES) 202

Social Turing Tests: Crowdsourcing Sybil Detection

As popular tools for spreading spam and malware, Sybils (or fake accounts) pose a serious threat to online communities such as Online Social Networks (OSNs). Today, sophisticated attackers are creating realistic Sybils that effectively befriend legitimate users, rendering most automated Sybil detection techniques ineffective. In this paper, we explore the feasibility of a crowdsourced Sybil detection system for OSNs. We conduct a large user study on the ability of humans to detect today's Sybil accounts, using a large corpus of ground-truth Sybil accounts from the Facebook and Renren networks. We analyze detection accuracy by both "experts" and "turkers" under a variety of conditions, and find that while turkers vary significantly in their effectiveness, experts consistently produce near-optimal results. We use these results to drive the design of a multi-tier crowdsourcing Sybil detection system. Using our user study data, we show that this system is scalable, and can be highly effective either as a standalone system or as a complementary technique to current tools

The COVID-19 Pandemic and the Technology Trust Gap

Industry and government tried to use information technologies to respond to the COVID-19 pandemic, but using the internet as a tool for disease surveillance, public health messaging, and testing logistics turned out to be a disappointment. Why weren’t these efforts more effective? This Essay argues that industry and government efforts to leverage technology were doomed to fail because tech platforms have failed over the past few decades to make their tools trustworthy, and lawmakers have done little to hold these companies accountable. People cannot trust the interfaces they interact with, the devices they use, and the systems that power tech companies’ services.This Essay explores these pre-existing privacy ills that contributed to these problems, including manipulative user interfaces, consent regimes that burden people with all the risks of using technology, and devices that collect far more data than they should. A pandemic response is only as good as its adoption, but pre-existing privacy and technology concerns make it difficult for people seeking lifelines to have confidence in the technologies designed to protect them. We argue that a good way to help close the technology trust gap is through relational duties of loyalty and care, better frameworks regulating the design of information technologies, and substantive rules limiting data collection and use instead of procedural “consent and control” rules. We conclude that the pandemic could prove to be an opportunity to leverage motivated lawmakers to improve our privacy frameworks and make information technologies worthy of our trust

U. S. Users’ Exposure to YouTube Videos On- and Off-platform

YouTube is one of the most important platforms on the Internet. However, it is not just a singular destination: because YouTube videos may be embedded into any website, it is a systemically important platform for the entire web. Unfortunately, existing studies do not examine playable YouTube videos embedded around the web, instead focusing solely on on-platform engagement. In this study we present the first comparison of on- and off-platform playable YouTube video exposure on the desktop web, based on data from a sample of n = 1133 U. S. residents from three cohorts: demographically representative users, heavy YouTube users, and users with high racial resentment. Our dataset includes the URLs of all playable YouTube videos encountered by participants for six months—on YouTube itself or embedded in another website—and the URLs where the videos were encountered. By analyzing this data, we find that less popular websites tend to embed YouTube videos in a disproportionately large percentage of their webpages and that individuals encounter more YouTube videos off-platform than on-platform. We also observe that most YouTube channels only receive exposure from either on- or off-platform sources, and that only-off-platform channels tend to get more exposure than only-on-platform ones. These results underscore the wide reach of YouTube as a service provider for the web and the limitations of studies focusing solely on on-platform activity. Motivated by concerns about online misinformation and hate speech, we also examine how partisan websites embed playable YouTube videos and where videos from problematic channels appear around the web. We find that politically right-leaning websites tend to embed more videos from problematic YouTube channels than centrist or left-leaning websites, and that participants exposed to off-platform videos from problematic channels are significantly more inclined to browse towards on-platform videos from problematic channels

Understanding the Role of Registrars in DNSSEC Deployment

The Domain Name System (DNS) provides a scalable, flexible name resolution service. Unfortunately, its unauthenticated architecture has become the basis for many security attacks. To address this, DNS Security Extensions (DNSSEC) were introduced in 1997. DNSSEC’s deployment requires support from the top-level domain (TLD) registries and registrars, as well as participation by the organization that serves as the DNS operator. Unfortunately, DNSSEC has seen poor deployment thus far: despite being proposed nearly two decades ago, only 1% of .com, .net, and .org domains are properly signed. In this paper, we investigate the underlying reasons why DNSSEC adoption has been remarkably slow. We focus on registrars, as most TLD registries already support DNSSEC and registrars often serve as DNS operators for their customers. Our study uses large-scale, longitudinal DNS measurements to study DNSSEC adoption, coupled with experiences collected by trying to deploy DNSSEC on domains we purchased from leading domain name registrars and resellers. Overall, we find that a select few registrars are responsible for the (small) DNSSEC deployment today, and that many leading registrars do not support DNSSEC at all, or require customers to take cumbersome steps to deploy DNSSEC. Further frustrating deployment, many of the mechanisms for conveying DNSSEC information to registrars are error-prone or present security vulnerabilities. Finally, we find that using DNSSEC with third-party DNS operators such as Cloudflare requires the domain owner to take a number of steps that 40% of domain owners do not complete. Having identified several operational challenges for full DNSSEC deployment, we make recommendations to improve adoption

Market or Markets? Investigating Google Search’s Market Shares under Vertical Segmentation

Is Google Search a monopoly with gatekeeping power? Regulators from the US, UK, and Europe have argued that it is based on the assumption that Google Search dominates the market for horizontal (a.k.a. “general”) web search. Google disputes this, claiming that competition extends to all vertical (a.k.a. “specialized”) search engines, and that under this market definition it does not have monopoly power. In this study we present the first analysis of Google Search’s market share under vertical segmentation of online search.We leverage observational trace data collected from a panel of US residents that includes their web browsing history and copies of the Google Search Engine Result Pages they were shown. We observe that participants’ search sessions begin atGoogle greater than 50% of the time in 24 out of 30 vertical market segments (which comprise almost all of our participants’ searches). Our results inform the consequential and ongoing debates about the market power of Google Search and the conceptualization of online markets in general