About Me

I am a third-year PhD candidate at the University of Exeter. My supervisors are Oliver Hauser and Daniele Rinaldo. Starting in September 2025, I will spend a year at Aix-Marseille School of Economics (AMSE).

My research interests lie in Political Economy and Behavioural Economics.

You can contact me at: J.Lamb3@exeter.ac.uk

Working Papers

• Media Misinformation and Childhood Vaccination – with O. Hauser and D. Rinaldo
  Abstract

  In 1998, The Lancet published an article that erroneously linked the Measles, Mumps, and Rubella (MMR) vaccine to autism. A media scare questioning the safety of the MMR vaccine followed. To analyze the effects of exposure to different reporting during this scare, we exploit exogenous variation in newspaper readership caused by the boycott of The Sun (England’s most widely read newspaper) in Liverpool. Using difference-in-differences and synthetic methods, we find that MMR vaccination rates fell 20% less in Liverpool compared to similar health authorities after the media scare. To analyze the reporting of newspapers around the time of the scare, we train word-embedding models on a corpus of newspaper articles. When compared to the most widely read newspaper in Liverpool after the boycott, The Sun’s reporting was more likely to drive fears about the vaccine, even when fraud surrounding the original Lancet paper became a major news story. In line with the natural language processing analysis, the differences in vaccination rates are largest for cohorts of children due to be vaccinated just after major events in the MMR scandal.

  
  

• Strategy of the Commons: Causal Evidence from a Lottery in Parliament – with C. Powell
  Abstract

  How do politicians secure top government positions? We exploit a natural experiment in the UK House of Commons, where Members of Parliament (MPs) submit their names to a ballot to win the opportunity to present and likely debate a bill of their choosing. We find that MPs that win the ballot are 71% (10.7 percentage points) more likely to hold high ranking jobs five years after the ballot, compared to MPs that submitted to the ballot but lost. Using their position in the ballot as an instrument, we provide causal evidence that this is not driven by ballot winners successfully converting bills into laws. Motivated by a simple model of political capital, we analyse the content of the bills using Natural Language Processing methods, to see if MPs are rewarded for using their bill to advance their party's objectives. In line with our model's predictions, we find that MPs presenting bills less similar to their previous speeches in Parliament are more likely to be young and, conditional on age, are more likely to have a high ranking job five years later.

  
  

• Closing the Gender Gap in Re-Applications for Senior Roles – with I. Bohnet, H.-Y. Chai, O. Hauser, and K. Louw (Reject & Resubmit at Management Science)
  Abstract

  We study the effects of behaviorally-informed interventions to close the gender gap in re-application rates to senior roles. We randomized 1,386 female and male applicants (“finalists”) who were recently rejected in the final assessment round for a senior role into three conditions: Control, Confidence, and Confidence+Commitment, providing finalists with confidence-boosting information and—for female finalists—indicating the organization’s commitment to increasing gender diversity. Both treatments closed the gender gap in re-application rates. However, the treatments differed in how they achieve this: in the Confidence+Commitment condition, women significantly increased their application rates by nearly 30% (10.9 percentage points), while in the Confidence condition, the gender gap closed because men’s re-application rates were lower. Our results inform future research on interventions to reduce gender gaps and offer a practical solution for organizations aiming to achieve gender parity in leadership.

  
  

Works in Progress

• Environmental Beliefs and Effort Between Generations – with H. Fornwagner and O. Hauser

• Stereotypes and Effort Provision in Teams – with A. McCrea and R. Tariq

• Giving More Together – with B. Grodeck and O. Hauser