State Space Models

All state space models are written and estimated in the R programming language. The models are available here with instructions and R procedures for manipulating the models here here.
Showing posts with label State Space. Show all posts
Showing posts with label State Space. Show all posts

Friday, September 5, 2025

World-System (1960-2100) A New "Axis of Evil"?

 


On September 1, 2025, in the Chinese port city of Tianjin, Chinese President Xi Jinping held a summit in response to the Trump II Administration tariff policies that included leaders of Russia and India and other representatives from the Global South (here). Xi declared that "Global governance has reached a new crossroads," in the fight against US Hegemonic Power. Did Xi just announce the birth of the New Axis of Evil? And, what might this mean for the future?

The conclusion from my World-System models is that the future forecasts for the New Axis of Evil all lead to collapse of the system (except for one worrisome scenario).

In prior posts (see the Notes below), I have looked at the issue of US Hegemonic Dominance and the economic performance of Russia, India and China. In this post, I will look specifically at how the three countries (RU, IN and CN) could interact with the current World-System.

The Measurement Matrix (see the Boiler Plate for more information about Dynamic Component Models) is presented in the Notes below. In terms of overall growth, the first growth components for each country are relatively equally weighted (AXIS1). The historical feedback controller (AXIS2) is dominated by Russia. From the graphic above, Russia's dominance peaked before 1990 and then decline after the Fall of the Soviet Union.
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For the late Twentieth Century, the system was dominated by the US. If that domination were to continue until 2100, the AXIS System would collapse--pretty strong motivation for eliminating US influence.


If the AXIS System were to align itself with the World-System (graphic above), the forecast for the future is also collapse.


If the AXIS System were to go it alone (as a BAU System), the countries could grow exponentially but it would involve the decline of the Russian historical feedback controller (AXIS2) -- a loss that would probably not be tolerated by Russia.


Unstable exponential growth will not minimize Environmental Damage from growth, so another option for an AXIS system not dominated by Russia is to stabilize growth (graphic above). Stability leads to a steady state after 2100 but would also probably not be tolerated by the AXIS participants.

In summary, none of the Geopolitical Alignments for the AXIS System look very promising. Either the system will eventually collapse or it's reason for existence (unending exponential growth) will not be consistent with World System Balance.

However, pursuing World System Balance does not seem to be a priority of any potential Hegemonic or Multipolar Leaders in the World-System.  In the Functionalist explanation, the AXIS System is necessary for the military-fueled expansion of all the participants .I will investigate the AXIS BAU scenario in a future post (here).

You can run the WL20_AXIS model here, the WL20_RU model here, the WL20_CN model here and the WL20_IN model here. 

You can run the AXIS_of_Evil models here.

Notes

Other relevant postings:



Monday, July 7, 2025

World-System (1950-2100+) Global Temperature Projections


May 26, 2026 Scientist Ditch Scary Climate Scenario Goodbye RCP8.5 (see below).

A Recent Paper in Nature Communications: Earth and Environment was titled Warming of +1.5 °C is too high for polar ice sheets.** In terms of projections from my models (above), this would mean that if we reach the 15.5 temperature level, it will be too late for the Polar Ice Caps to maintain their integrity and sea level rise will inundate most countries around the World (to include Mar-a-Lago, President Trumps Empire). Does this mean catastrophe for the World-System? 

The first projection to consider is the Random Walk (RW). If Global Temperature were a  Random Walk it would mean that it cannot be forecast, a result that would please Climate Change Deniers. Given the high variability of the Global Temperature data, it should be no surprise that, in the short-run year-to-year, Global Temperature is a RW given the Akaike Information Criterion [-77.33, AIC=-65.15,-55.0]. However, in the long-run there is a clear trend. The issue is how far into the future can the trend be carried.

In the Stokes (2025) Global Sea Level article the conclusion is that, to prevent destabilizing the Arctic Ice Caps, Global Temperature should return to the levels somewhere around the 1980's. The graphic above plots a forecast of the Temperature WL203 BAU model that has no inputs (no radiative forcings). Without forcings from human systems (anthropogenic forcings) the model would say within the "safe" zones. Unfortunately, isolating Global Temperature from human systems seems impossible.



The next one of my models to consider simply uses CO2 emissions to predict global temperature, something similar to the endpoint of the Kaya Impact Model (graphed above) used by the IPCC. The model projects a linear increase in temperature that eventually reaches a steady state (the model is stable). Using the Akaike Information Criterion (smaller is better) [170.2,AIC=198.3 217.1], it is not a strong competitor.

Another important model involves the technical coefficients of the Kaya Impact Model (q, e, c, t in the graphic above). The model is important because improvements in Kaya Technology (efficiency) such as renewable energy, etc. should ultimately reduce Global Temperature. The model shows continuing increases in Global Temperature, but because the model is stable, a steady state will eventually be reached but at a higher Global Temperature than 15.5 degrees (dotted red line in first graphic). In other words, even though technological change can moderate temperatures, it will not be enough to prevent melting of the Polar Ice Caps. Still, the model is a good competitor using the Akaike Information Criterion [-47.94, AIC=14.95, 67.81].*** 

Finally, driving Global Temperature with the state of the World System using two different models (the dashed blue line and the pink line in the graphic at the beginning of this post), produce growth-and-collapse modes and keep global temperature below 15.5 degrees. The WL203 model (dashed blue line) is the best model (beyond the RW) using the Akaike Information Criterion  [-70.95, AC=-10.41, 34.52] compared to the WL20W model [-4.007, AIC=64.63, 107.9].

You can experiment with the stable WL203 model (here) or the unstable WL20W model (here).


Notes

WL203 Measurement Model


The measurement model for the World System has three historical environmental controllers: W1=(Growth-LivingPlanet), W2=(LivingPlanet-TEMP) and W3=(P.Oil.-TotalFootprint).  Information about the indicators (LivingPlanet index, Global TEMP, TotalFootprint), etc. can be found in the Boiler Plate.

** Recent data from NASA's CRES (Clouds and Earth’s Radiant Energy System) satellite data also indicates that Earth's Albedo (ability to reflect sunlight and reduce warming) is decreasing!

*** There is another type of Technological change that involves productivity (the dashed black line in the graphic at the beginning of this article). It shows a similar, if somewhat worse, time path than Kaya Technology and reaches 15.5 degrees earlier in time.


RCP2.6 to RCP8.5


Although there has been a lot of controversy surrounding RCP8.5 (Scientist Ditch Scary Climate Scenario), one point to make about the graphic above is that there is no Unlimited-Exponential-Growth-Forever scenario which seems to be what Climate Deniers predict will happen. Neoclassical Economists (see the DICE model) argue that growth will be limited when Technological change (Productivity) and Population growth reach  steady state (See the Solow-Swan Neoclassical Growth Model below).


Solow-Swan Growth Model





The Solow-Swan Neoclassical Growth Model (It is the basis for the DICE model) is one of the most important macro models in economics (along with the AS-AD Supply-Demand model). The directed graph above shows that the two exogenous causal variables are Population (N) and Technology (TECH). If either of these variables stop growing, the system will reach a Steady State Economy. It may be surprising to students of Economics to learn that, from a causality standpoint), Labor (L), Production (Q) and Capital Stock (K) are purely dependent variables and are not the primary drivers of growth.

UN Population projections currently anticipate that Population will peak at 10.3 Billion people in 2084. In order to reach steady steady, the  DICE model has to also assume (arguably) that Technology Change will also peak at some time in the future.