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Gustav Delius
Works at University of York, Applied Mathematics
Attended State University of New York at Stony Brook
Lives in York
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Gustav Delius

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I used plotly to make a graph: https://plot.ly/~GustavDelius/16/greek-trade-balance-since-1948 . Plotly is a really nice tool for creating graphs quickly interactively.

I was never able to understand how a small country like Greece with only 11 million inhabitants could have accumulated a debt of 330 billion Euros (33,000 euros per inhabitant). Hence I downloaded the trade data from the WTO. It shows an average deficit of 40 billion dollars per year over the last 12 years. That is almost 4,000 dollar for every inhabitant every year. In such a situation debts mount quickly.

The graph below is in US Dollar in current prices. It does not show accumulated deficit but new deficit made every year. 
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Just a thought: Greece has a lot of coastline. They should probably spend a lot of money on their navy and coastguard.
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We had an interesting talk about Cassava disease today. I must admit that I had never heard of Cassava before. It turns out to be a basic food source for 500 million people. It is somewhat similar to sweet potatoes but excellent for subsistence farming because of its drought resistance, its ability to grow in poor soil, and the fact that one can leave the tubers in the ground until one wants to eat them so that there is no danger of spoilage.
The excellent talk by +Christopher Finn McQuaid from Rothamsted Research was about modelling the spread of Cassava brown streak disease. This disease can lead to a 75% reduction in yield. One way for the disease to spread over longer distances is through the trading of the planting material. The plants are propagated from cuttings of parent plants. If the parent was infected, so will the offspring. It is therefore important to get disease-free planting material to farmers. This is the kind of problem where the mathematical models must take into account not only the ecological factors but also the social factors, in this case how farmers obtain and select their planting material from other farmers. The researchers are therefore planning to collaborate with #sociologists to design appropriate surveys to get at the information.
+Lukas Delius : It turns out that one of the countries most affected by the disease is #Uganda. 
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This article discusses the phenomenon that economists are heard much more than sociologists in the media and that sociologists are often not even consulted by the government when their expertise is clearly relevant. The problem is not that newspapers do not discuss sociological topics. There is a lot of discussion of topics like crime, family, gender equality, discrimination, xenophobia, ... The problem is just that sociological experts are not consulted for these topics, whereas economists are always consulted for economic topics. 

Unfortunately this article does not explain well what led to the prominence of the economists over sociologists, so it is not clear what to do to change things. But one problem seems to be that prominent sociologists in the past tended to be politically biased towards the left, i.e., tended to be anti-establishment. This has very much shaped the public's image of sociologists and makes it difficult for sociologists to be consulted as objective scientific experts. There is a lot of mistrust to be overcome, especially in the more conservative sections of society. 
 
My latest: How economists came to dominate the conversation.
http://www.nytimes.com/2015/01/24/upshot/how-economists-came-to-dominate-the-conversation.html
A search of the archives of The New York Times finds that the use of the term “economist” rose in the past century, outpacing “historian.”
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+Gustav Delius thanks, from this I am tempted conclude that there isn't really an increase in mentions of social scientists, just economists. But I will play more with this later.
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The article describes the problem well, but does not talk about solutions. But raising awareness of the problem is a good first step. 
 
»Efficiency solves nothing while growth continues.«
Time for #PlanP as in #Postgrowth  
George Monbiot: It's the great taboo of our age – and the inability to discuss the pursuit of perpetual growth will prove humanity's undoing
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We are hiring again. I am looking forward to interacting with two new colleagues in Mathematical Biology soon. In addition, we have also advertised a statistics lectureship.
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Gustav Delius

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Fifty years ago, LBJ gave an amazing speech arguing that America shouldn't pursue economic growth but rather community, nature, leisure time, and happiness.
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Next Friday, September 26th, is the European Researchers' Night. 300 cities across Europe are organising events to bring an understanding of current research to the wider public. The range of events and talks that York is putting on for the night is quite impressive, The talk by our own +Roger Colbeck on quantum cryptography is just one of over 30 scientific talks across York that evening.

If you do not live in York, you can use the map at http://ec.europa.eu/research/researchersnight/events_en.htm to check out whether your nearest city is organising something similar.
YorNight 2014 is York’s part of European Researchers’ Night which is happening in 300 EU cities on 26 September. YorNight will host a variety of activities and events for all ages.
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Once again an example that shows that we should give also social scientists more training in basic mathematical thought.

This book by Thomas Piketty has made quite a splash and spent many weeks near the top of the amazon best sellers list. The book is published by Harvard University Press and the author is professor at the École des hautes études en sciences sociales and professor at the Paris School of Economics. So tonight I decided I should have a look. 

The first chapter contains the following clear statement: "This fundamental inequality, which I will write as r > g (....) will play a crucial role in this book. In a sense, it sums up the overall logic of my conclusions". The text in parenthesis left out in my quote above even gives a definition of r and g. So I thought this was going to be a book I would like. A book that could be summarised with a simple inequality involving two quantities r and g whose definition I can understand.

Here are the definitions I left out above: "...(where r stands for the average annual rate of return on capital, including profits, dividends, interest, rents, and other income from capital, expressed as a percentage of its total value, and g stands for the rate of growth of the economy, that is, the annual increase in income or output)...". From this definition we see that r has dimensions 1/time and g has dimensions 1/time^2 (the annual increase in annual income). 

Do you see the problem? Should the inequality r >  g be expected to be meaningful even though r and g have different dimensions? No. A natural scientist will spot this problem immediately. I am dreaming of a future where the same will be true of social scientists.

I now want to decide whether I should continue reading the book. Perhaps Professor Piketty only made a mistake when trying to condense his theory into a simple inequality. Maybe a more meaningful theory will be developed later in the book. If you have read beyond the first chapter, can you advise me whether it is worthwhile to read on?
The main driver of inequality--returns on capital that exceed the rate of economic growth--is again threatening to generate extreme discontent and undermine democratic values...
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+Jean-Marc Schlenker, I am happy to hear that. In fact, all the economists I know have very good mathematical training. As pointed out by +Jyotirmoy Bhattacharya in his comments above, Piketty only made what one could call a typo. That happens with the best mathematical training. 
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Github has become even better for researchers, with free private repositories and DOIs for your code.

If your research involves any computation, I hope you are already using Github to host your research code so that others can reproduce your research and build on it. Github is also a particularly useful place to keep your code while you are working on it together with your collaborators.

Up to now there was always the small problem that the free Github accounts only allowed public repositories, where anyone could watch you while you were developing your code. This is not always desirable. With the new research accounts you get 5 free private repositories.
GitHub is being used today to build scientific software that's helping find Earth-like planets in other solar systems, analyze DNA, and build open source rockets. Seeing these projects and all this momentum within academia has pushed us to think about how we can make GitHub a better tool for research. As scientific experiments become more complex and their datasets grow, researchers are spending more of their time writing tools and software to a...
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+Tony Sidaway , thank you for the tip. Given the competition from Bit Bucket, one can understand why Github starts giving free private repositories as well.
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+Ben Lambert , a private tutor and Ph.D. student in computational biology in Oxford, has made Khan Academy style videos constituting a course in econometrics. I listened in on the first few lectures on multi-linear regression and they were very clear and would be very accessible to our second-year undergraduate students at York. He also has an undergraduate version that will probably be suitable to recommend to my students when I teach our first-term Introduction to Probability and Statistics again in the autumn.

I found out about these video lectures because Ben Lambert had an ad for them running before the latest Minute Physics video on YouTube. What an enterprising Ph.D. student!
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Awesome find! Thank you for sharing +Gustav Delius. 
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Our final-year project students are now using the Easter break to write their project reports. In our last meeting I briefed them on the importance of being both clear and concise in their writing. I wish I could have been as eloquent as Schopenhauer in formulating this advice.
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:-) Yes, Schopenhauer's prose is pleasant to read but not brief. A more useful place that I direct some of my students to are the first few lectures in the course "Writing in the Sciences" at https://www.coursera.org/course/sciwrit
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Education
  • State University of New York at Stony Brook
    Theoretical Physics, 1985 - 1990
  • Universität Bielefeld
    Mathematics and Physics, 1983 - 1985
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01904 323 077
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Department of Mathematics University of York York YO10 5DD
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Applied Mathematician: Theoretical Ecology, Stochastic Processes, Symmetry
Introduction
My background is in Quantum Field Theory, String Theory, Integrable Systems and Quantum Groups. My current research is in transferring some of the methods of these fields to theoretical ecology.

Two concrete current research topics are:
  • Scale invariant size spectrum models of the pelagic ecosystem.
  • Modelling extinction trajectories in microcosm communities.
I also have a wider interest in stochastic processes and complex networks.
Work
Occupation
Lecturer in Mathematics
Skills
Stochastic Modelling, Spatial Stochastic Processes, Quantum Field Theory, String Theory, Integrable Systems and Quantum Groups
Employment
  • University of York, Applied Mathematics
    Lecturer in Mathematics, present
  • Bielefeld University
    Hochschulassistent
  • King's College London
    EPSRC Advanced Research Fellow
  • CERN
    Visiting Scientist
  • Brandeis
    Postdoc
  • State University of New York at Stony Brook
    Research Assistant
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Map of the places this user has livedMap of the places this user has livedMap of the places this user has lived
Currently
York
Previously
Bielefeld - Boston - London - Geneva - Stony Brook
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