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Thea Don-Siemion  BA, MSc, PhD

Dr Thea Don-Siemion


BA, MSc, PhD


Cardiff Business School

Aberconway Building, Floor 4th, Room T32, Colum Road, Cathays, Cardiff, CF10 3EU


I am a Lecturer in Economics at Cardiff University, having completed my PhD in Economic History at the London School of Economics.  My research focuses on the spread of the Great Depression throughout Europe and the reasons why the Depression affected certain countries more than others.

I am particularly interested in explaining the unusual level of volatility in the economy of the Polish Second Republic (1918-1939), which faced not only a hyperinflation between 1918 and 1924, but also a Great Depression identified by Romer (1991) to have been as severe as in the much-better studied case of the United States.

My PhD thesis finds that the major reason for Poland's poor performance during the 1930s was the country's adherence to the gold standard for geopolitical reasons: the maintenance of the military alliance with France.  I am currently working, with William A. Allen, on a book-length history of Polish central banking between the two World Wars.





Research Interests:

  • Interwar Economic History
  • Monetary and Financial Macroeconomics 
  • Sovereign Debt Crises
  • Hyperinflations
  • International Political Economy
  • Central and Eastern Europe 


Current Teaching Responsibilities:

  • BS2572: State, Business, and the British Economy in the 20th Century.

Teaching Interests:

  • 19th and 20th Century Economic History
  • Monetary History
  • Undergraduate Macroeconomics and Econometrics


2023 – Present: Lecturer in Economics, 
Cardiff University/Prifysgol Caerdydd.

2021 – 2023: Fellow, College Teaching Officer in Economics, and Director of Studies, 
Gonville and Caius College, University of Cambridge

2016 – 2022: PhD in Economic History,
London School of Economics
(Thesis title: Money, Debt and the Balance of Payments in Poland’s Great Depression).

Honours and awards

  • Economic History Society Bursary Scheme for PhD Students, £2000, 2020/21.

Professional memberships

  • Cliometric Society – Full Member
  • Economic History Association – Full Member
  • Economic History Society – Full Member
  • European Historical Economics Society – Full Member

Speaking engagements

  • 54. Deutscher Historikertag, "The Currency as a Weapon of War: The Polish Hyperinflation of 1918-1924 and the Difficulties of Peacemaking in Central Europe".  Invited speaker.  Leipzig, Germany, 9/2023.
  • Goethe University, Frankfurt, “Hyperinflation and Stabilisation in Poland, 1919 - 1927." Invited speaker, Conference on New Lessons from the Archives: The Evolving History of Central Banking, 6/2023.
  • Gonville and Caius College, University of Cambridge, MCR-SCR Seminar, “Hyperinflation and Stabilisation in Poland, 1919 - 1927." 2/2023.
  • Economic History Society Annual Conference, “Interwar Poland’s Late Exit from Gold: A Case of Government as ‘Conservative Central Banker?’”.  University of Warwick, 4/2021
  •  Queen’s University Belfast, “Interwar Poland’s Late Exit from Gold”.  Invited speaker, QUCEH Seminar Series. 1/2021
  •  Rutgers University, “Interwar Poland’s Late Exit from Gold”.  Invited speaker, Workshop in Money, History, and Finance. 11/2020.

Committees and reviewing

  • European Review of Economic History: Peer Reviewer (2021 - Present)


  • 20th Century
  • Banking, finance and investment
  • Economic history
  • Central and Eastern European History
  • Macroeconomics

External profiles