Research Work

Publications & Work in progress

My research work focuses on digital economics. I aim to provide insights on the value of data and consumer privacy. Since they might conflict with each other, my research aims to describe (i) consumer profiling on the Internet, (ii) derive a price of privacy, (iii) analyze the impact of strategies such as a data tax on the value of data and consumer privacy, and (iv) assess the impact of the General Data Protection Regulation on the Online Advertising Industry. Nevertheless, I do not hesitate to cross scientific borders to conduct research on other topics such as analyzing mitigation strategies of COVID-19.

Digital Economics

Summary of Articles

Despite the importance of consumer profiles for advertisers, surprisingly little is known regarding their breadth, depth, density, and consistency. The article „Velocity, Density, and Consistency of Third-Party Consumer Profiling“ provides those insights based on a random sample of nearly 54,000 consumers tracked by a major European ad exchange.

While consumer data are essential for modern data-driven advertising strategies, their collection and usage raise privacy concerns. Therefore, some firms adopted a concept called „differential privacy“ to reduce data accuracy, increasing consumer privacy. The article „Price of Privacy for Online Advertising“ provides the economic consequences of differential privacy based on almost 8,000,000 bids from 535 advertisers.

Regulators all over the world introduce new privacy laws to decrease the amount of personal data processed by firms. Yet, some firms are not compliant, and some data processing might simply be too valuable to restrict it. The article „Does Even a Small Data Tax Increase Consumer Privacy“ proposes a data tax to incentivize firms not to provide or use personal data for targeting. It simulates the impact of a tax on consumer privacy and the decrease in the value of targeting.

While the new privacy laws emerge, their impact on the different actors in the online advertising market remains unclear. The article „The Impact of the General Data Protection Regulation (GDPR) on the Online Advertising Industry“ (i) outlines how the online advertising industry operates. It uses the European General Data Protection Regulation (GDPR) as the first of a handful of one rather strict privacy laws to illustrate the (ii) economic impact of GDPR and (iii) how to process personal data for online advertising legally and technically. The manuscript also (iv) provides empirical insights into the complexity of the industry and the decision cost of the users.

Status of Articles

Kraft, L., Miller, K. & Skiera, B. “Velocity, Density, and Consistency of Third-Party Consumer Profiling. Under 1st round of revise and resubmit in Journal of Marketing.

Kraft, L. “Price of Privacy for Online Advertising”. Work in progress.

Kraft, L. “Does Even a Small Data Tax Increase Consumer Privacy?“. Work in progress.

Skiera, B., Miller, K., Kraft, L., Schmitt, J., Laub, R., Jin, Y. “The Impact of the General Data Protection Regulation (GDPR) on the Online Advertising Market“. Work in progress.

Nutrition, Health and Covid-19

Description of Articles

Prior studies indicate the protective role of Ultraviolet-B (UVB) radiation in human health, mediated by vitamin D synthesis. The articles of my co-authors and me outline a negative association of UVB radiation as measured by ultraviolet index (UVI) with the number of COVID-19 deaths. To assess the associations‘ robustness, the article tests whether the association vanishes if people stay inside due to due to natural phenomena such as monsoon and non-pharmaceutical public health measures such as lockdowns.


Status of Articles

Moozhipurath, R.K., Kraft, L. & Skiera, B. “Evidence of protective role of Ultraviolet-B (UVB) radiation in reducing COVID-19 deaths”. Scientific Reports 10, 17705 (2020).

Moozhipurath, R.K., Kraft, L. “Implications of Monsoon Season and UVB Radiation for COVID-19 in India”. Scientific Reports 11, 2757 (2021).

Moozhipurath, R.K., Kraft, L. “Does Lockdown Decrease the Protective Role of Ultraviolet-B (UVB) Radiation in Reducing COVID-19 Deaths?”. Under 1st round of review in Scientific Reports.


Policy Analysis

Description of Article

Many western countries aim to fill labor-market shortages via residence permits for high-skilled workers. The Blue Card represents the european approach of attracting high-skilled labor and the article „Work Permit Regulations and Labor Market Outcomes“ evaluates its impact on student graduates in Germany. More specifically, it finds that the Blue Card did not incentivize more graduates to stay. Instead, it increases their labor market entry wages via the permit’s inherent salary threshold. The article provides suggestive evidence that the graduates use this threshold als a reference point when entering the job market.

Status of Article

Qendrai, P., Kraft, L. “Work Permit Regulations and Labor Market Outcomes”. Work in progress.


Lennart Kraft



Raum 1.202 im RuW-Gebäude
Theodor-W.-Adorno-Platz 4
D-60323 Frankfurt am Main