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Reposted by Karsten Kohler

Karsten Kohler @karstenkohler.bsky.social · 06/10/2026

New section on the DIY Macroeconomic Model Simulation Website: An Endogenous Housing Cycle Model macrosimulation.org/an_endogenou... (1/6)

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Karsten Kohler @karstenkohler.bsky.social · 06/10/2026

The cycle arises from a Neimark-Sacker bifurcation in a nonlinear 2D system. The section provides a detailed numerical and analytical discussion of the model, which complements the business cycle models by Kaldor and Hicks already covered on the website. (6/6)

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Karsten Kohler @karstenkohler.bsky.social · 06/10/2026

If extrapolation is weak, a price shock dies out in damped oscillations. If it is strong, the steady state becomes unstable: extrapolation drives the price away from its fundamental value, mean reversion pulls it back, and a permanent cycle emerges. (5/6)

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Karsten Kohler @karstenkohler.bsky.social · 06/10/2026

Some speculators extrapolate deviations of the house price from its fundamental value, others expect a return to it. The further the price moves away from its fundamental value, the more speculators switch to the mean-reverting rule. (4/6)

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Karsten Kohler @karstenkohler.bsky.social · 06/10/2026

The model features a housing market in which prices adjust to excess demand, construction responds positively to prices, and demand consists of a real and a speculative component. Speculators are boundedly rational and rely on simple forecasting rules. (3/6)

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Karsten Kohler @karstenkohler.bsky.social · 06/10/2026

New section on the DIY Macroeconomic Model Simulation Website: An Endogenous Housing Cycle Model macrosimulation.org/an_endogenou... (1/6)

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Reposted by Karsten Kohler

Karsten Kohler @karstenkohler.bsky.social · 29/09/2026

New section on the DIY Macroeconomic Model Simulation Website: The Dornbusch Exchange Rate Overshooting Model macrosimulation.org/a_dornbusch_... (1/6)

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Karsten Kohler @karstenkohler.bsky.social · 29/09/2026

In both cases, stability is not the result of an economic adjustment process but imposed by assuming that agents rationally coordinate on the non-explosive path. The section provides a detailed numerical and analytical discussion of this type of model. (6/6)

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Karsten Kohler @karstenkohler.bsky.social · 29/09/2026

Technically, the equilibrium is a saddle point, and the exchange rate is a ‘jump variable’ that lands on the unique stable path. The section carefully explains this technique that is also at the heart of modern New Keynesian monetary policy models. (5/6)

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Karsten Kohler @karstenkohler.bsky.social · 29/09/2026

After a monetary expansion, the interest rate falls. Investors will only hold domestic bonds if they expect an appreciation. So the exchange rate first depreciates beyond its new long-run level and then gradually appreciates – it overshoots. (4/6)

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Karsten Kohler @karstenkohler.bsky.social · 29/09/2026

The model features a small open economy with perfect capital mobility, sticky goods prices, and a flexible exchange rate. Expectations are rational: investors correctly anticipate the future path of the exchange rate. (3/6)

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Karsten Kohler @karstenkohler.bsky.social · 29/09/2026

The section shows how to simulate in R / Python the classic exchange rate overshooting model by Dornbusch (1976), which aims to explain why exchange rates can be much more volatile than the fundamentals that are assumed to drive them. (2/6)

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Karsten Kohler @karstenkohler.bsky.social · 29/09/2026

New section on the DIY Macroeconomic Model Simulation Website: The Dornbusch Exchange Rate Overshooting Model macrosimulation.org/a_dornbusch_... (1/6)

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Reposted by Karsten Kohler

Jo Michell @jomichell.bsky.social · 21/09/2026

Not sure there are many Kalecki heads on this website but I'm going to give this a try anyway. If this isn't your cup of tea, you might want to hit mute now...

A journal cover page for "An analytical heterogeneous agent macro model of concentration, markups, and falling labour shares" by Karsten Kohler, Jo Michell and Ayoze Alfageme, published in the Journal of Economic Dynamics and Control.

The abstract text is: This paper presents an analytical heterogeneous agent model (HAM) to explore micro-level concentration dynamics and their effects on macro-level distribution and growth. It contributes to recent work on macroeconomic agent-based models (ABMs) by comparing a small-scale ABM with bilateral firm-customer matching to a simplified HAM without direct agent interactions. The HAM replicates key ABM results while allowing for analytical solutions. In the model, larger firms benefit from lower unit costs due to economies of scale, gain larger market shares, and set higher markups. More profitable firms temporarily grow faster, leading to endogenous changes in the firm size distribution. The resulting right-skewed distributions create a divergence between the average profit share across firms and the aggregate profit share, which is driven by the largest firms. The decline in the labour share reduces aggregate consumption and slows growth. Despite its simplicity, the model captures key empirical patterns related to superstar firms and declining labour shares.

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Reposted by Karsten Kohler

Karsten Kohler @karstenkohler.bsky.social · 10/09/2026

New paper with @jomichell.bsky.social and Ayoze Alfageme: “An analytical heterogeneous agent macro model of concentration, markups & falling labour shares” www.sciencedirect.com/science/arti... 1/6

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Karsten Kohler @karstenkohler.bsky.social · 10/09/2026

Thanks Ruben! :-) Although doing the maths for this paper also gave me some grey hairs...

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Karsten Kohler @karstenkohler.bsky.social · 10/09/2026

Open access article available here: www.sciencedirect.com/science/arti...

sciencedirect.com

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Karsten Kohler @karstenkohler.bsky.social · 10/09/2026

Aggregate effects: a falling aggregate labour share, weaker consumption demand, and slower growth. 6/6

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Karsten Kohler @karstenkohler.bsky.social · 10/09/2026

This skew creates a gap between the average profit share across firms and the aggregate profit share, which is driven by the largest firms. Concentration raises the profit share. A pattern that has been documented empirically in the literature on "superstar firms". 5/6

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Karsten Kohler @karstenkohler.bsky.social · 10/09/2026

Core model mechanism: larger firms have lower unit costs from economies of scale → bigger market share → higher markups. More profitable firms grow faster, so the firm-size distribution becomes increasingly right-skewed. 4/6

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Karsten Kohler @karstenkohler.bsky.social · 10/09/2026

We show that the simplified HAM (w/o direct agent interactions) gives qualitatively similar results to a small-scale ABM (w/ direct firm-customer interaction), while allowing for analytical solutions. 3/6

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Karsten Kohler @karstenkohler.bsky.social · 10/09/2026

We build a heterogeneous agent model (HAM) to explore micro-level concentration dynamics and their effects on macro-level distribution and growth. 2/6

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Karsten Kohler @karstenkohler.bsky.social · 10/09/2026

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Reposted by Karsten Kohler

Tom Bauermann @bauermann-tom.bsky.social · 01/06/2026

‼️Extended Deadline‼️ 📢 Call for papers 📅 🥳 #30FMM Conference "Shaping macroeconomics in times of global Transformation" When and Where? 22-24 Oct 2026, Berlin Deadline for abstracts? 14 June (Correct date) We look forward to your abstract. More information: www.imk-boeckler.de/de/aktuelle-...

imk-boeckler.de

Shaping macroeconomics in times of global transformation: 30 years of FMM

Das Institut für Makroökonomie und Konjunkturforschung (IMK) hat es sich zum Ziel gesetzt, der gesamtwirtschaftlichen Perspektive in der ökonomischen Forschung und in der wirtschaftspolitischen Diskus...

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Reposted by Karsten Kohler

Post-Keynesian Economics Society @pkes.bsky.social · 27/04/2026

📢 2026 𝐏𝐊𝐄𝐒 Annual Workshop 📍King's College London, King’s Building, Room 204 📅19 May 13:30 to 18:30 (BST) Speakers include @devikadutt.bsky.social, @ggouzoulis.bsky.social, Katie Kedward, Olga Mikheeva, @thomasrab.bsky.social and Hamisu Salihu. 𝐅𝐮𝐥𝐥 𝐝𝐞𝐭𝐚𝐢𝐥𝐬: www.postkeynesian.net/event/2026-0...

postkeynesian.net

2026 Annual workshop | PKES

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Karsten Kohler @karstenkohler.bsky.social · 07/04/2026

Leeds University Business School (LUBS) are offering two‑year Post Doctoral Fellowship Schemes. The Economics department at LUBS is committed to pluralism and conducts research along a range of theories and methods, including macro-finance. Deadline is 31 May. jobs.leeds.ac.uk/vacancy.aspx...

jobs.leeds.ac.uk

Job Opportunity at University of Leeds: Faculty Post Doctoral Fellowships, Leeds University Business School

Are you an aspiring researcher looking to further your career in one of the UK’s leading research-intensive Universities and receive a structured programme of support? Do you have a research backgrou...

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Reposted by Karsten Kohler

Karsten Kohler @karstenkohler.bsky.social · 03/04/2026

New open-access article with Engelbert Stockhammer and Ben Tippet in Socio-Economic Review -- 'What goes up, must come down: speculation-encouraging institutions and house price cycles across countries' (1/5) academic.oup.com/ser/advance-...

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Karsten Kohler @karstenkohler.bsky.social · 03/04/2026

We find that low capital gains taxes and strong landlord-protection policies that may push households onto the property ladder are linked to more intense house price booms and busts. (5/5)

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Karsten Kohler @karstenkohler.bsky.social · 03/04/2026

In an empirical analysis for 23 OECD countries, we explore the role of speculation-encouraging institutions, credit permissiveness, welfare state regimes and macroeconomic policy as potential factors. (4/5)

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Karsten Kohler @karstenkohler.bsky.social · 03/04/2026

Bringing Minskyan and behavioural theories of endogenous financial cycles to CPE, we argue that the intensity of house price booms and busts is shaped by institutions that encourage speculative behaviour, such as low capital gains taxes and strong landlord-protection policies. (3/5)

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Karsten Kohler @karstenkohler.bsky.social · 03/04/2026

We provide a Comparative Political Economy (CPE) perspective on boom-bust cycles in house prices. Cycles in house prices are large relative to their trend, and the intensity of house price cycles differs across countries. (2/5)

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Karsten Kohler @karstenkohler.bsky.social · 03/04/2026

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Reposted by Karsten Kohler

Post-Keynesian Economics Society @pkes.bsky.social · 28/03/2026

📣 2026 PKES Summer School (21–24 June, University of Greenwich, London) Spend 3 days exploring Post-Keynesian Economics & Political Economy. Topics include money & finance, inequality, fiscal policy, feminist econ, development & ecological macro. Apply now 👇 www.postkeynesian.net/event/2026-p...

postkeynesian.net

2026 Summer School - Introduction to Post Keynesian Economics and Political Economy | PKES

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Reposted by Karsten Kohler

Together Alliance @togetheralliance.bsky.social · 28/03/2026

Half a million strong. Together. The biggest march against the far-right in British history.

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University and College Union (UCU) @ucu.org.uk · 12/03/2026

Join our bloc at the @UKTogetherAll march on 28 March! 🙌 Assemble 12pm, Block C. Find us on what3words: ///patrol.cone.pulse March with us against the far right ✊ Full route info: togetheralliance.org.uk

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Reposted by Karsten Kohler

Zack Polanski @zackpolanski.bsky.social · 07/03/2026

Over 1000 civilians dead, and we're letting Trump use UK bases to further his war. Britain should stand firm against Trump's illegal warmongering, and stop these bombers landing on UK soil.

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University and College Union (UCU) @ucu.org.uk · 21/01/2026

UCU is deeply concerned by the length of time people connected to alleged actions involving Palestine Action are being held on remand. Read the full statement 👇

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Karsten Kohler @karstenkohler.bsky.social · 12/01/2026

In case you're teaching the Solow model this semester, check this out 👇

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Reposted by Karsten Kohler

Karsten Kohler @karstenkohler.bsky.social · 11/12/2025

New section on the DIY Macroeconomic Model Simulation Website: The Solow Growth Model macrosimulation.org/a_solow_model (1/5)

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Karsten Kohler @karstenkohler.bsky.social · 11/12/2025

While arguably of very limited real-world relevance, the Solow model is still widely taught. The section provides a detailed numerical and analytical discussion of a continuous-time version of the model, which might be helpful for teaching and learning. (6/6)

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Karsten Kohler @karstenkohler.bsky.social · 11/12/2025

When introducing exogenous labour-saving technical change, the model generates per-capita output growth also in the long run. (5/6)

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Karsten Kohler @karstenkohler.bsky.social · 11/12/2025

The production function exhibits constant returns to scale but diminishing marginal returns to its individual inputs. As a result, it only generates long-run growth in total output, but not in output per capita, which only grows during the adjustment towards the steady state. (4/6)

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Karsten Kohler @karstenkohler.bsky.social · 11/12/2025

The model considers a supply-driven growth process with a neoclassical aggregate production function with capital and labour as substitutable inputs. There is no independent investment function: all saving is automatically invested. (3/6)

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Karsten Kohler @karstenkohler.bsky.social · 11/12/2025

The section shows how to simulate in R / Python the canonical neoclassical growth model due to Solow (1956) (2/6).

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Karsten Kohler @karstenkohler.bsky.social · 11/12/2025

New section on the DIY Macroeconomic Model Simulation Website: The Solow Growth Model macrosimulation.org/a_solow_model (1/5)

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Alasdair Mackenzie @alasdairmackenzie.bsky.social · 15/11/2025

To reiterate, this is about making life immeasurably more miserable and stressful for some of the most vulnerable people, in the almost certainly vain hope of winning over the votes of racists. Anything more shabby and shameful is difficult to envisage.

independent.co.uk

Asylum in UK to be made temporary under Home Secretary’s plans

Shabana Mahmood will lay out reforms modelled on the Danish system on Monday.

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Reposted by Karsten Kohler

JW Mason @jwmason.bsky.social · 14/11/2025

Interestingly, this is not true. Nice example of one of the central analytic pitfalls in this area, confusing net flows with gross ones.

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