@book{60595,
  abstract     = {{Many of the major international and intrastate crises and conflicts, but also the threat to democratic principles, are driven by belief systems and ideologies. They fuel political polarization, which is particularly evident in the battleground of social media. Nevertheless, we hardly pay attention to ideologies, their narratives, functions and organizations in economic theory today. Ideologies as “non-rational beliefs” seem incompatible with rationality in economic models. 

Therefore, the book examines the role of ideologies and belief systems in individual decision-making behavior from an economic and rational perspective. Due to the fact that people have incomplete information, belief systems and ideologies fulfill a number of important functions. While ideologies themselves serve psychological needs, they are used as a cognitive framework for rational decision-making once they have been adopted through a Bayesian learning process. They influence decisions in a wide range of areas, from consumption and work to politics. This is where the role of ideological organizations becomes important, because they determine the ideological direction of the narratives and their dissemination. 

Thus, ideologies give a normative direction, for better or for worse. The “quality” of ideological leadership can be evaluated normatively on the basis of principles such as individual sovereignty and human dignity. A democratic discourse requires an information and communication system that enables an evaluation of precisely these ideologies, free from resource and information power.
}},
  author       = {{Gries, Thomas and Burs, Carina and Müller, Veronika}},
  isbn         = {{9783031935138}},
  issn         = {{2731-5908}},
  publisher    = {{Springer Nature Switzerland}},
  title        = {{{The Economics of Ideologies}}},
  doi          = {{10.1007/978-3-031-93514-5}},
  year         = {{2025}},
}

@article{50719,
  abstract     = {{We propose an indicator for detecting anomalous stock market valuation in real time such that market participants receive timely signals so as to be able to take stabilizing action. Unlike existing approaches, our anomaly indicator introduces three methodological novelties. First, we use an endogenous, purely data-driven, nonparametric trend identification method to separate long-term market movements from more short-term ones. Second, we apply SETAR models that allow for asymmetric expansions and contractions around the long-term trend and find systematic stock price cycles. Third, we implement these findings in our indicator and conduct real-time market forecasts, which have so far been neglected in the literature. Applications of our indicator using monthly S&P 500 stock data from 1970 to the end of 2022 show that short-term anomalous market movements can be identified in real time up to one year ahead. We predict all major anomalies, including the 1987 Bubble and the initial phase of the Financial Crisis that began in 2007. In total, our anomaly indicator identifies more than 80% of all – even minor – anomalous episodes. Thus, smoothing market exaggerations through early signaling seems possible.}},
  author       = {{Fritz, Marlon and Gries, Thomas and Wiechers, Lukas}},
  issn         = {{1469-7688}},
  journal      = {{Quantitative Finance}},
  keywords     = {{General Economics, Econometrics and Finance, Finance}},
  pages        = {{1--14}},
  publisher    = {{Informa UK Limited}},
  title        = {{{An early indicator for anomalous stock market performance}}},
  doi          = {{10.1080/14697688.2023.2281529}},
  year         = {{2024}},
}

@book{56154,
  abstract     = {{<jats:p>Is Artificial Intelligence a more significant invention than electricity? Will it result in explosive economic growth and unimaginable wealth for all, or will it cause the extinction of all humans? Artificial Intelligence: Economic Perspectives and Models provides a sober analysis of these questions from an economics perspective. It argues that to better understand the impact of AI on economic outcomes, we must fundamentally change the way we think about AI in relation to models of economic growth. It describes the progress that has been made so far and offers two ways in which current modelling can be improved: firstly, to incorporate the nature of AI as providing abilities that complement and/or substitute for labour, and secondly, to consider demand-side constraints. Outlining the decision-theory basis of both AI and economics, this book shows how this, and the incorporation of AI into economic models, can provide useful tools for safe, human-centered AI.</jats:p>}},
  author       = {{Naudé, Wim and Gries, Thomas and Dimitri, Nicola}},
  isbn         = {{9781009483094}},
  publisher    = {{Cambridge University Press}},
  title        = {{{Artificial Intelligence}}},
  doi          = {{10.1017/9781009483094}},
  year         = {{2024}},
}

@article{60118,
  author       = {{Fritz, Marlon and Forstinger, Sarah and Feng, Yuanhua and Gries, Thomas}},
  issn         = {{0266-4763}},
  journal      = {{Journal of Applied Statistics}},
  number       = {{7}},
  pages        = {{1342--1360}},
  publisher    = {{Informa UK Limited}},
  title        = {{{Forecasting economic growth by combining local linear and standard approaches}}},
  doi          = {{10.1080/02664763.2024.2424920}},
  volume       = {{52}},
  year         = {{2024}},
}

@inbook{58364,
  author       = {{Kolosok, Svitlana and Myroshnychenko, Iuliia and Gries, Thomas}},
  booktitle    = {{The Elgar Companion to Energy and Sustainability}},
  isbn         = {{9781035307494}},
  publisher    = {{Edward Elgar Publishing}},
  title        = {{{Energy and sustainability: a balanced energy transition strategy}}},
  doi          = {{10.4337/9781035307494.00024}},
  year         = {{2024}},
}

@book{54545,
  abstract     = {{<jats:title>Abstract</jats:title>
               <jats:p>This book combines theoretical and empirical research across various academic disciplines, including economics, psychology, neuroscience, philosophy, and political science, to describe why individuals adopt political ideologies and how this choice can potentially exacerbate conflict and violence. Ideology is particularly important to conflict. Data on intra- and international conflict shows that the number of ideologically driven conflicts has increased tremendously in recent decades. Although some researchers have started to investigate extensively the link between ideology and conflict, they struggle to find holistic explanations through which ideologies might shape conflict. This book addresses this effort by providing an interrelated multidisciplinary framework to explain the multidimensional functions of ideology. It illustrates that ideologies are not only capable of shaping conflictual behavior or mobilizing political actors, but also of addressing human needs, desires, and preferences. Hence, this book seeks to explain how individuals adopt ideologies that match their underlying needs and preferences; that ideologies have the capacity to reconcile deprived psychological human needs; and that radical groups and organizations use ideologies to recruit individuals and pursue their objectives. To understand these relationships better and to apply the theoretical background to real-world situations, we include real-life cases that describe how depriving individuals of resources that satisfy their underlying needs and preferences can lead them to adopt particular ideologies that are disseminated by radical groups or organizations. These radical groups or organizations then make decisions, which can potentially lead to conflict onset and continuous long-term struggles.</jats:p>}},
  author       = {{Müller, Veronika and Gries, Thomas}},
  isbn         = {{0197670180}},
  publisher    = {{Oxford University PressNew York}},
  title        = {{{Ideology and the Microfoundations of Conflict}}},
  doi          = {{10.1093/oso/9780197670187.001.0001}},
  year         = {{2024}},
}

@article{49309,
  abstract     = {{I study the effect of heterogeneous beliefs about asset prices on the long-term behavior of financial markets. Starting from the ideas of Abreu and Brunnermeier (Citation2003), a two-dimensional system of differential equations is developed. The first dynamic variable is the asset price growth rate. The second dynamic variable is the number of investors who believe that asset prices are abnormally high. In a phase plane analysis, I find both stable and unstable equilibria, depending on the spread of information and the response to other agents’ beliefs. If individuals try to increase their returns while perceiving more overpricing, these equilibria can be spirals or even approach limit cycles. Although I intend to study general price patterns, abnormally high asset prices can be caused by financial bubbles. In this model, bubbles can emerge and deflate both in cycles or directly, or they can grow until they burst. Further, I analyze market behavior after a central bank increases the interest rate. This can lead to new stable equilibria, but the emergence and bursting of bubbles cannot be prevented.}},
  author       = {{Burs, Carina}},
  issn         = {{2332-2039}},
  journal      = {{Cogent Economics & Finance}},
  keywords     = {{asset pricing, subjective information, stability conditions, monetary policy, risk aversion}},
  number       = {{2}},
  publisher    = {{Informa UK Limited}},
  title        = {{{A model of cycles and bubbles under heterogeneous beliefs in financial markets}}},
  doi          = {{10.1080/23322039.2023.2272485}},
  volume       = {{11}},
  year         = {{2023}},
}

@article{48086,
  abstract     = {{Individuals strive to make decisions that are consistent with not only their consumer preferences but also their psychological needs. However, they are confronted with complex, ambiguous or even false information. Ideologies and belief systems provide guidance when processing and evaluating information and give a coherent and comprehensible interpretation of reality. The first question is: why is an individual attracted to a particular ideology? Individuals choose ideologies that resonate with their subjective psychological needs and preferences. Second, how do individuals search for ideologies and find out which suit them best? We model an individual’s sequential information search for the best matching ideologies by applying Bayesian learning and utility optimization. Additional information enhances utility by reducing uncertainty. As a search is costly, the process may stop once an individual adopts an ideology even if the information set remains incomplete. Third, once they have chosen a particular ideology, individuals adhere to its rules and norms when making everyday decisions. Consumers not only physically consume, but they also act in accordance with their psychological needs.}},
  author       = {{Burs, Carina and Gries, Thomas and Müller, Veronika}},
  issn         = {{2158-3609}},
  journal      = {{Journal of Organizational Psychology}},
  keywords     = {{Economics, Ideology, Decision-making}},
  number       = {{1}},
  publisher    = {{North American Business Press}},
  title        = {{{The Choice of Ideology and Everyday Decisions}}},
  doi          = {{10.33423/jop.v23i1.6033}},
  volume       = {{23}},
  year         = {{2023}},
}

@article{44591,
  abstract     = {{<jats:title>Abstract</jats:title><jats:p>The ability of various policy activities to reduce the reproduction rate of the COVID-19 disease is widely discussed. Using a stringency index that comprises a variety of lockdown levels, such as school and workplace closures, we analyze the effectiveness of government restrictions. At the same time, we investigate the capacity of a range of lockdown measures to lower the reproduction rate by considering vaccination rates and testing strategies. By including all three components in an SIR (Susceptible, Infected, Recovery) model, we show that a general and comprehensive test strategy is instrumental in reducing the spread of COVID-19. The empirical study demonstrates that testing and isolation represent a highly effective and preferable approach towards overcoming the pandemic, in particular until vaccination rates have risen to the point of herd immunity.</jats:p>}},
  author       = {{Fritz, Marlon and Gries, Thomas and Redlin, Margarete}},
  issn         = {{2199-9023}},
  journal      = {{International Journal of Health Economics and Management}},
  keywords     = {{Health Policy, Economics, Econometrics and Finance (miscellaneous)}},
  publisher    = {{Springer Science and Business Media LLC}},
  title        = {{{The effectiveness of vaccination, testing, and lockdown strategies against COVID-19}}},
  doi          = {{10.1007/s10754-023-09352-1}},
  year         = {{2023}},
}

@article{33221,
  abstract     = {{<jats:title>Abstract</jats:title><jats:p>Non-pharmaceutical interventions are an effective strategy to prevent and control COVID-19 transmission in the community. However, the timing and stringency to which these measures have been implemented varied between countries and regions. The differences in stringency can only to a limited extent be explained by the number of infections and the prevailing vaccination strategies. Our study aims to shed more light on the lockdown strategies and to identify the determinants underlying the differences between countries on regional, economic, institutional, and political level. Based on daily panel data for 173 countries and the period from January 2020 to October 2021 we find significant regional differences in lockdown strategies. Further, more prosperous countries implemented milder restrictions but responded more quickly, while poorer countries introduced more stringent measures but had a longer response time. Finally, democratic regimes and stronger manifested institutions alleviated and slowed down the introduction of lockdown measures.</jats:p>}},
  author       = {{Redlin, Margarete}},
  issn         = {{0922-680X}},
  journal      = {{Journal of Regulatory Economics}},
  keywords     = {{Economics and Econometrics}},
  publisher    = {{Springer Science and Business Media LLC}},
  title        = {{{Differences in NPI strategies against COVID-19}}},
  doi          = {{10.1007/s11149-022-09452-9}},
  year         = {{2022}},
}

@article{33220,
  abstract     = {{<jats:title>Abstract</jats:title><jats:p>We provide a partial equilibrium model wherein AI provides abilities combined with human skills to provide an aggregate intermediate service good. We use the model to find that the extent of automation through AI will be greater if (a) the economy is relatively abundant in sophisticated programs and machine abilities compared to human skills; (b) the economy hosts a relatively large number of AI-providing firms and experts; and (c) the task-specific productivity of AI services is relatively high compared to the task-specific productivity of general labor and labor skills. We also illustrate that the contribution of AI to aggregate productive labor service depends not only on the amount of AI services available but on the endogenous number of automated tasks, the relative productivity of standard and IT-related labor, and the substitutability of tasks. These determinants also affect the income distribution between the two kinds of labor. We derive several empirical implications and identify possible future extensions.</jats:p>}},
  author       = {{Gries, Thomas and Naudé, Wim}},
  issn         = {{2510-5019}},
  journal      = {{Journal for Labour Market Research}},
  keywords     = {{General Medicine}},
  number       = {{1}},
  publisher    = {{Springer Science and Business Media LLC}},
  title        = {{{Modelling artificial intelligence in economics}}},
  doi          = {{10.1186/s12651-022-00319-2}},
  volume       = {{56}},
  year         = {{2022}},
}

@article{33219,
  author       = {{Gries, Thomas and Müller, Veronika and Jost, John T.}},
  issn         = {{1047-840X}},
  journal      = {{Psychological Inquiry}},
  keywords     = {{General Psychology}},
  number       = {{2}},
  pages        = {{65--83}},
  publisher    = {{Informa UK Limited}},
  title        = {{{The Market for Belief Systems: A Formal Model of Ideological Choice}}},
  doi          = {{10.1080/1047840x.2022.2065128}},
  volume       = {{33}},
  year         = {{2022}},
}

@article{22715,
  abstract     = {{<jats:title>Abstract</jats:title><jats:p>Using data from the German Socio-Economic Panel for 1984–2018, we analyze the intergenerational education mobility of immigrants in Germany by identifying the determinants of differences in educational stocks for first- and second-generation immigrants in comparison to individuals without a migration background. Our results show that on average, first-generation immigrants have fewer years of schooling than native-born Germans and have a disproportionate share of lower educational qualifications. This gap is strongly driven by age at immigration, with immigration age and education revealing a nonlinear relationship. While the gap is relatively small among individuals who migrate at a young age, integrating in the school system at secondary school age leads to large disadvantages. Examining the educational mobility of immigrants in Germany, we identify an inter-generational catch-up in education. The gap in education between immigrants and natives is reduced for the second generation. Finally, we find that country of origin differences can account for much of the education gap. While immigrants with an ethnic background closer to the German language and culture show the best education outcomes, immigrants from Turkey, Italy, and other southern European countries and especially the group of war refugees from Syria, Afghanistan, Iraq and other MENA countries, have the lowest educational attainment.</jats:p>}},
  author       = {{Gries, Thomas and Redlin, Margarete and Zehra, Moonum}},
  issn         = {{1488-3473}},
  journal      = {{Journal of International Migration and Integration}},
  title        = {{{Educational Assimilation of First-Generation and Second-Generation Immigrants in Germany}}},
  doi          = {{10.1007/s12134-021-00863-9}},
  year         = {{2021}},
}

@article{23594,
  abstract     = {{<jats:title>Abstract</jats:title><jats:p>Using time series data for the period 1959–2015, our empirical analysis examines the simultaneous effects of the individual components of the global carbon budget on temperature. Specifically, we explore the possible effects of carbon emissions caused by fossil fuel combustion, cement production, land-use change emissions, and carbon sinks (here in terms of land sink and ocean sink) on climate change. The simultaneous inclusion of carbon emissions and carbon sinks allows us to look at the coexistent and opposing effects of the individual components of the carbon budget and thus provides a holistic perspective from which to explore the relationship between the global carbon budget and global warming. The results reveal a significant positive effect of carbon emissions on temperature for both fossil fuels emissions and emissions from land-use change, confirming previous results concerning carbon dioxide and temperature. Further, while ocean sink does not seem to have a significant effect, we identify a temperature-decreasing effect for land sink.</jats:p>}},
  author       = {{Redlin, Margarete and Gries, Thomas}},
  issn         = {{0177-798X}},
  journal      = {{Theoretical and Applied Climatology}},
  title        = {{{Anthropogenic climate change: the impact of the global carbon budget}}},
  doi          = {{10.1007/s00704-021-03764-0}},
  year         = {{2021}},
}

@article{33667,
  abstract     = {{<jats:title>Abstract</jats:title><jats:p>In light of the COVID-19 pandemic, we scrutinize what has been established in the literature on whether entrepreneurship can cause and resolve extreme events, the immediate and long-run impacts of extreme events on entrepreneurship, and whether extreme events can positively impact (some) entrepreneurship and innovation. Based on this, we utilize a partial equilibrium model to provide several conjectures on the impact of COVID-19 on entrepreneurship, and to derive policy recommendations for recovery. We illustrate that while entrepreneurship recovery will benefit from measures such as direct subsidies for start-ups, firms’ revenue losses, and loan liabilities, it will also benefit from aggregate demand-side support and income redistribution measures, as well as from measures that facilitate the innovation-response to the Keynesian supply-shock caused by the pandemic, such as access to online retail and well-functioning global transportation and logistics.</jats:p>}},
  author       = {{Gries, Thomas and Naudé, Wim}},
  issn         = {{2511-1280}},
  journal      = {{Economics of Disasters and Climate Change}},
  keywords     = {{General Medicine}},
  number       = {{3}},
  pages        = {{329--353}},
  publisher    = {{Springer Science and Business Media LLC}},
  title        = {{{Extreme Events, Entrepreneurial Start-Ups, and Innovation: Theoretical Conjectures}}},
  doi          = {{10.1007/s41885-021-00089-0}},
  volume       = {{5}},
  year         = {{2021}},
}

@article{17072,
  author       = {{Feng, Yuanhua and Gries, Thomas and Fritz, Marlon}},
  issn         = {{1048-5252}},
  journal      = {{Journal of Nonparametric Statistics}},
  pages        = {{510--533}},
  title        = {{{Data-driven local polynomial for the trend and its derivatives in economic time series}}},
  doi          = {{10.1080/10485252.2020.1759598}},
  year         = {{2020}},
}

@article{17074,
  author       = {{Gries, Thomas and Grundmann, Rainer}},
  issn         = {{1363-6669}},
  journal      = {{Review of Development Economics}},
  pages        = {{644--667}},
  title        = {{{Modern sector development: The role of exports and institutions in developing countries}}},
  doi          = {{10.1111/rode.12663}},
  year         = {{2020}},
}

@article{17086,
  author       = {{Gries, Thomas and Redlin, Margarete}},
  issn         = {{1612-4804}},
  journal      = {{International Economics and Economic Policy}},
  pages        = {{923--944}},
  title        = {{{Trade and economic development: global causality and development- and openness-related heterogeneity}}},
  doi          = {{10.1007/s10368-020-00467-1}},
  volume       = {{17}},
  year         = {{2020}},
}

@article{2808,
  author       = {{Gries, Thomas and Jungblut, Stefan and Krieger, Tim and Meyer, Henning}},
  journal      = {{German Economic Review}},
  number       = {{2}},
  pages        = {{129--170}},
  title        = {{{Economic Retirement Age and Lifelong Learning - a theoretical model with heterogeneous labor and biased technical change}}},
  doi          = {{10.1111/geer.12140}},
  volume       = {{20}},
  year         = {{2019}},
}

@article{9920,
  author       = {{Fritz, Marlon and Gries, Thomas and Feng, Yuanhua}},
  issn         = {{0165-1765}},
  journal      = {{Economics Letters}},
  pages        = {{47--50}},
  title        = {{{Secular stagnation? Is there statistical evidence of an unprecedented, systematic decline in growth?}}},
  doi          = {{10.1016/j.econlet.2019.04.021}},
  volume       = {{181}},
  year         = {{2019}},
}