Just as almost all mathematics is nonlinear, almost all economic phenomena are complex. (Doyne Farmer)

# Claudius Gräbner’s Academic Homepage¶

## Welcome to my academic homepage¶

I am currently a research associate at the Institute for Comprehensive Analysis of the Economy (ICAE) at the Johannes Kepler University Linz (Austria) and a researcher at the Institute for Inclusive and Sustainable Economies (ZOE).

My research is concerned with the effects of globalization, the determinants for international competitiveness of countries, economic complexity, institutions and development.

Since I am very interested in mathematics and programming I try to integrate them into my work as an economist. Many of my models are therefore computational and the (meta-theoretical) question of how we can create knowledge about the real world by building and studying computational models is also one of my favorite questions to think and write about.

Currently, I frequently give presentations and workshops on topics related to my research. The material of my invited talks and keynotes can be found in the section presentations. I taught courses on microeconomics, in particular game theory, information and institutional economics, but also on macroeconomics and economic complexity. I also taught seminars in computational economics and econometrics. You can have a look on the corresponding material in the teaching section.

You may also check out the news section, read some more or less interesting stuff about myself, and get my public PGP key.

## New working paper on measures of economic openness¶

Posted August 18

While working on a project that studies the socio-economic effects of the openness of economies, we figured out that there are a vast number of different measures for openness. Therefore, we wrote a review entitled Measuring Economic Openness: A review of existing measures and empirical practices in which we present, discuss and compare various measures for openness. We also provide for a taxonomy of such measures and show with a practical example that the choice of the measure is very important for the outcome of any quantitative analysis of economic openness.

## New article on complexity and pluralism¶

Posted July 31 2018

My paper The Complexity of Economies and Pluralism in Economics has now been published in the Journal of Contextual Economics.

In the paper I argue that - for ontological and epistemological reasons - pluralism with regard to economic research programs is a more viable position to hold than monism. Also, I discuss channels through which power accumulation of research programs under the current institutions takes place, and that this accumulation process is self-reinforcing. Thus, without critical intervention, the scientific system self-organizes itself towards an (epistemologically inferior) state of unity.

For a non-barrier version of the paper see the accepted manuscript.

## New working paper on pluralism in economics¶

Posted August 6 2018

Together with Birte Strunk I published a new working paper entitled ‘’Pluralism in Economics: Its critiques and their lessons’‘. We discuss five common argument against pluralism and try to provide adequate responses. We also try to identify the ‘lessons to be learned’ by pluralists and argue that the most important challenges for pluralists is to think about strategies that ensure communicatino across paradigms, and about the development of cross-paradigmatic quality indicators.

## Launch of a video-based introduction ABM in Python¶

Posted July 19 2018

I have launched this video-based introduction to ABM in Python. It consists of scripts, and videos explaining hands-on the content of the scripts. The course is addressing people who want to learn agent-based modelling, but do not want to use a specialized platform such as Netlogo.

Thus, the course aims to teach people without previous experience in programming both the basics in the programming language Python, and the basics of agent-based modelling using Python.

For now, the videos are only available in German, but the scripts are also available in English (see the English course homepage).

For any video block there is a feedback form, and I greatly value your feedback on this course.

This feedback will not only help me to improve the course in the future, but also build a good English version of the course.

I hope you find the information helpful and become as fascinated by programming and ABM as I do!

## New presentation on theory development in economics and lessons for ABM scholars¶

Posted July 9 2018

I was invited to give talk during this great symposium on theory development with agent-based models.

My presentation is about how economists construct theory, and what lessons we can learn from this process - in the positive as well as in the negative sense. The slides are available here (some pictures removed for potential copyright issues).

Who is interested in these kind of questions might also have a look at my new paper on model validation and verification in JASSS.

As always, any feedback is highly appreciated.

## New paper on ABM and institutional analysis¶

Posted July 1 2018

My paper To Trust or to Control: Informal Value Transfer Systems and Computational Analysis in Institutional Economics has now been published in the Journal of Economic Issues.

The paper , which is joint work work with Wolfram Elsner and Alex Lascaux, introduces an agent-based model to study the role of trust and control for the functioning of informal money transfer systems such as Hawala.

We place in the application into a broader discussion on how agent-based models can be used for institutional analysis and how they can improve communication among different research programs.

## New paper on the epistemology of model verification and model validation¶

Posted July 1 2018

How do we relate models with reality? What is meant by model verification and validation? When and why are these activities important? These are some of the questions that I explore in my paper How to Relate Models to Reality? An Epistemological Framework for the Validation and Verification of Computational Models , which has now been published (open access) in JASSS.

Not only deals the paper with some important epistemological questions underlying the use of computational models, it also serves as a non-technical introduction of epistemological concepts to non-philosophers and applied modellers.

## New presentation on path dependent development in Europe¶

Posted April 15 2018

I recently gave an invited presentation at the conference Renewal of the European Economic Integration Concept , held at the University of Szeged, Hungary. The slides are available here .

The presentation is mainly based on the paper Structural change in times of increasing openness: assessing path dependency in European economic integration (see below).

## New working paper on structural change and path dependent development in Europe¶

Posted February 16 2018

In the paper Structural change in times of increasing openness: assessing path dependency in European economic integration we study the impacts of increasing European integration. We estimate the reactions of countries to an increase in trade and financial openess and find that the effects on different countries are very heterogeneous. Based on this finding we propose a taxonomy of European economies that consists of core, periphery, financialized and catch-up countries. Studying the structural changes in these countries in more detail we suggest that development tractories in Europe are highly path dependent and relate to the sectoral development of European economies and the evolution of their technological capabilities. This has important implications for policy making.

## New article on agent-based and equation-based modeling¶

Posted November 16 2017

Together with my friends Catherine Bale, Bernardo Alves Furtado, Brais Alvarez-Pereira, James E. Gentile, Heath Henderson and Francesca Lipari , who I all met at the Complex Systems Summer School of the Santa Fe Institute, I published an article in Computational Economics. It is open access and the title is Getting the Best of Both Worlds? Developing Complementary Equation-Based and Agent-Based Models.

The paper deals with the distinction between equation-based and agent-based models, and ways to fruitfully combine them. We apply to our ideas to a model by Acemoglu and Robinson on the Kuznets Curve.

One cool thing about building and ABM from an EBM is that you concern yourself very deeply with the logic of the original model. In our case this helped us to discover some analytical mistakes in the original model, which we have described in this comment.

## Presentation on unrealistic models at the TINT workshop in Helsinki¶

Posted October 25 2017

I was honored to give a presentation at the workshop What to Make of Highly Unrealistic Models? at the Academy of Finland Centre of Excellence in the Philosophy of Social Sciences.

My presentation was about the various ways models can be termed ‘unrealistic’ and when and how they can still be useful. You can have a look at my presentation here and read a summary of my argument here. I greatly appreciate, as always, any feedback!

## Material on Summer Course on Computational Economics and Complexity¶

Posted October 25 2017

This summer I was happy to teach a one-week course on complexity economics and computational methods together with Torsten Heinrich from Oxford University. The Summer Academy is related to Exploring Economics, a wonderful pluralistic economics learning plattform. All the material is available here. Any feedback is, as always, highly welcome.

## New working paper on European disintegration¶

Posted July 26 2017

In the paper Is Europe disintegrating? Macroeconomic divergence, structural polarization, trade and fragility we study the uneven development in Europe since 2000. The basic argument is that European countries follow two different growth trajectories, a debt-led trajectory in the periphery, and an export-led trajectory in the core. We trace the reasons to this to the different level of competitiveness of firms and the technological capabilities in the countries. Our conclusion is that European countries must implement three types of policies simultaneously: macroprudential financial regulation, industrial policy, and progressive redistribution.

The paper is available here and feedback is, as always, highly appreciated.

## New working papers: One on informal economic exchange and one on the epistemology of model verification/validation¶

Posted June 15 2017

I recently finished two working papers: The deals with the functioning of informal economic exchange systems, in particular the value transfer system Hawala. It’s title is Trust and Social Control. Sources of cooperation, performance, and stability in informal value transfer systems. It uses computational experiments to settle an important ambiguity with regard to the stabilizing mechanisms in such systems: is it mainly social control of general trust that is at the core of the system’s stability?

The second is entitled How to relate models to reality? An epistemological framework for the validation and verification of computational models. and takes a more theoretical approach. It suggests an epistemological framework for the validation and verification of computational models. This way, it hopefully contributes to a better understanding and a better comparability of different simulation models.

Feedback on both of them is highly appreciated!