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.

Saturday, April 19, 2025

World-System (1300-1450): The German Economy


 
One of the most important points to understand about Germany is that until 1871 Unification, Germany was a collection states and part of the Holy Roman Empire. Cities were connected by crude trading routes and the size of the cities was limited by the difficulties of long term trade. Urbanization (DE3=(U-N) above) was a strong limiting factor in economic development for the period prior to 1450 (see the graphic above). Growth did not begin accelerating until 1409. And the period prior to 1409 was a long-developing Malthusian Crisis (U-N) that limited expansion.

The period from 1300-1400 is sometimes called the Crisis of the Middle Agesdemographic collapse, political instability and religious upheaval. The Great Famine of 1315–1317 and the Black Death of 1347–1351 potentially reduced the European population by half or more as the Medieval Warm Period came to a close and the first century of the Little Ice Age began and unity of the Catholic Church was threatened by the Western SchismIn Germany between 1336 and 1525 there was widespread and militant peasant unrest.   Both the Urbanization ECC and the Malthusian ECC worked together to limit growth up to 1409. 

Economically, the period after 1300 in the graphic above was dominated by the  Hanseatic League which declined after 1450. Hanseatic trade involved both maritime, in-land waterway and overland trade.

State Space Models for the period (1300-1450) can be found here.  A discussion of the period after 1450 can be found here.


Notes


The measurement matrix for the state space model is presented above. DE1=(Growth), DE2=(Q-N-U) and DE3=(U-N), that is Growth, the Urban-Malthusian Controller and the Urbanization Controller (A discussion of Error Correcting Controllers, ECCs, can be found here).

Thursday, April 17, 2025

World-System (1450-1640): The German Economy

 



The expansion of the German Economy after 1450 (a discussion of the period before 1450 can be found here)  was brought to an end by the Urbanization Controller (Q-U) which peaked about 1550 which was also associated with a mild Malthusian crisis (Q-N). Eventually, growth reached a plateau after 1600.

During the early part of the Long Sixteenth Century (1450-1650), the Great Bullion Famine also limited economic growth. Precious metals were necessary to conduct overland and maritime commerce and the European mines were being played out. The voyages of Columbus were motivated by the search for gold necessary to mint coin.


Notes


The measurement matrix for the DEL16 state space model is presented above showing the weightings for the Urbanization (0.634 Q - 0.768 U) and the Malthusian (0.524 Q - 0.7821 N) Error Correcting Controllers (ECCs).



The system matrix for the DEL16 state space model is presented above. The model is unstable (dominant eigenvalue greater than 1.0). The model can be stabilized by reducing the coefficient for the Urbanization ECC (F[2,2] = 1.017812347) or you can turn the Urbanization and the Malthusian ECCs into random walks by setting (F[2,2] = F[3,3] = 1.0).



The result of setting the ECCs to random walks is to create a cyclical system (see the forecast above). What is interesting is that this cyclical system, without German Unification in 1871, enters the Twentieth Century, right before WWI, on a downward cycle. Germany would have been unable to wage war without Unification (see Pasdirtz, 1981).

State Space models for the period (1450-1640) can be found here.




Boiler Plate



State Space Model Estimation

The Measurement Matrix for the state space models was constructed using Principal Components Analysis with standardized data from the World Development Indicators. The statistical analysis was conducted in an extension of the dse package. The package is currently supported by an online portal (here) and can be downloaded, with the R-programming language, for any personal computer hereCode for the state space Dynamic Component models (DCMs) is available on my Google drive (here) and referenced in each post.


Atlanta Fed Economy Now

My approach to forecasting is similar to the EconomyNow model used by the Atlanta Federal Reserve. Since the new Republican Administration is signaling that they would like to eliminate the Federal Reserve, the app might well not be available in the future.


While the app is still available, there have been some interesting developments. In earlier forecasts, the Atlanta Fed was showing GDP growth predictions outside the Blue Chip Consensus. Right now, after unorthodox economic policies from the Trump II Administration, the EconomyNow model is predicting a drastic drop in GDP (the Financial Forecast Center is only predicting a slight drop here).

Climate Change

Another comparison for what I have presented above are the IPCC Emission Scenarios. These scenarios are for the World System. Needless to say, (1) the new Right-Wing Republican administration plans on withdrawing the US from all attempts to study or ameliorate Climate Change and (2) the IPCC does not produce any RW modes for the World System (but seem my forecasts here).


World System

The longest running set of data we have for the World-System is the Maddison Project based on the work of Angus Maddison (more information is available here). Data on production (Q) and population (N) for most countries and regions runs from years 0-2000. More data becomes available as we near the year 2000. 


Available data were entered in a spreadsheet (see Population above, double click to enlarge). Missing data were interpolated with nonlinear spline smoothing using the R programming Language.


In cases where initial values were not available (see GDP above), the E-M Algorithm was used to estimate initial conditions.

From the graph of GDP above (W_Q) for the World System, it can be seen that economic growth from the year 0-1500 was basically flat. The period of British Capitalism (after 1500) had a small plateau of growth. Takeoff does not happen until the Nineteenth Century.



From a system's perspective, the only model that can be tested for the entire period is Kenneth Boulding's Malthusian Systems Model [Q,N] = f[Q,N].



When developed as a State Space model (measurement matrix above) there are two components: W1=Growth and W2=(Q-N), the Malthusian Controller. When more data is available, the Malthusian Controller can be generalized to other SocioEconomic theories.

What the Malthusian Controller shows (plotted as Q-N above) is that a long-developing Malthusian Crisis (Q<N) started in the Late Middle Ages and accelerated through the period of British Capitalism (Dark Satanic Mills) and was reversed spectacularly during the Nineteenth Century.  Takeoff in response to a deepening Malthusian Crisis would not be an unreasonable way to view Modern Economic Growth.

Error Correcting Controllers (ECC)


In another post (here), I presented Leibenstein's Malthusian Error Correcting Controller (ECC). It can be generalized to the dominant ECCs in most theoretical economic models (above). These controllers can be further generalized. For example, (X-U) and (L-U) can be generalized to (N-U), a more general Urbanization Controller which describes market expansion for economic growth. In countries and periods with limited data, (N-U) might subsume all these processes. ECCs describe important feedback processes in SocioTechnical System that are typically not recognized as such in academic literature.

Kaya Identity


The basic theoretical model underlying all the World-System models I crate is the Kaya Identity. There are a number of advantages to starting theoretical development with the Kaya Identity: (1) An "identity" is true by definition Adding other variables to the model ensure that theory construction is on a solid footing. (2) The Kaya Identity is also used as the foundation for the IPCC Emissions Scenarios allowing a linkage between World-Systems Theory and the work of the IPCC.


World Development Indicators (WDI)



After WWII, extensive data sets on all countries in the World-System became available from the World Bank (here). The indicators above where chose to construct the state space for each WDI-based model. Addition indicators can be added for specific forecasts and analyses.

Friday, March 14, 2025

World-System (1950-2010): The Ukrainian Economy

 

What framework can we use for understanding the Economy of Ukraine: (1) A World-System Perspective, (2) a Neoclassical Economic Growth Perspective, (3) A Classical Economic Perspective (Marx, Malthus, Adam Smith, etc.), (4) A General Systems Perspective? Systems Theory includes all these perspectives but gives the data a chance to identify what gorwth and control components are of primary importance to the Economy.





Notes




You can run the full UAL20 BAU model here and explore the other Error Correcting Controllers (ECC) which have complicated Malthusian elements.

Tuesday, January 14, 2025

Black Box, Isomorphic Cybernetic Systems

 


Cybernetics played an important role in the development and control of mechanical-electric systems but did not gain traction in the Social Sciences.



Notes

Ashby, Ross (1956) An Introduction fo Cybernetics, (pdf file).

Lange, Oskar (1970) Introduction to Economic Cybernetics (pdf file).


Easton, David (1900) The Political System

Saturday, December 14, 2024

A Simple Basic Causal Macro Impact Model

 

George E. P. Box (1919-2013) was a statistician at the University of Wisconsin--Madison.

Economists are having trouble with macroeconomic models (I posted about the topic here). Macroeconomic modeling got off track by requiring that models have micro-foundations based on expectations, meaning that macro-societal economic forces had to be derived from the individual decisions of economic agents, for example, you and me buying groceries. Unfortunately, there are lots of different ways expectations can be formed (rational expectations, model-consistent expectations, adaptive expectations, etc.)  From the perspective of macro Systems Theory, micro-foundations make a logical category error. "Expectations" are not an attribute of macro-systems but of economic agents. The decision has led to a dead end in macro-economic modeling.

Having a solid basis for macro-modeling makes all sorts of sense. You would like the causal foundations of your theories to be true by definition.* Actually, there are three causal models that macro-economics could be based upon, that is, used to derive other, more complicated models.  They are the Kaya Identity, the Solow-Swan Model of economic growth**, and the AD-AS (Aggregate Demand-Aggregate Supply) Market Model.








NOTES

* In logic, a statement that is true by definition is a tautology.

** Actually, the Solo-Swan model can be derived from the Kaya Identity, so we really only need two models.

Code

If you would like to run the R program in your web browser, cut and paste the following code into the editor window at https://rdrr.io/snippets/.

Kaya <- function (time=100,N=100,n=1.4,L=50,Q=100,q=1.04,CO2=1,
Temp=1,l=.5,e=.75,c=.0002,t=.0001,limit=1) UseMethod ("Kaya")
Kaya.default <- function (time=100,N=100,n=1.4,L=50,Q=100,q=1.04,CO2=1,
Temp=1,l=.5,e=.75,c=.02,t=.01,limit=1) {
TEMP <- matrix(0,time,1)
TIME <- matrix(0,time,1)
for (i in 1:time) {
N <- N * n;
L <- N * l;
Q <- Q * q + L * e;
CO2 <- Q * c;
Temp <- CO2 * t;
TEMP[i,1] <- Temp;
TIME[i,1] <- i;
if (i > time/2) {c <- c * limit}
}
plot(TIME,TEMP)
}
par(mfrow=c(2,2))
# Sample Function Calls
Kaya(n=1.03,q=1.04)
title(main="Exponential")
Kaya(n=.9,q=1)
title(main="Asymptote")
# De-Growth
Kaya(n=.9,q=.9)
title(main="Degrowth")
# Decline
Kaya(n=.6,q=.6)
title(main="Decline")
Kaya(n=1.03,q=1.04,limit=0.95)
title(main="IPCC Slow")
Kaya(n=.9,q=1,limit=0.95)
title(main="IPCC Fast")

Monday, November 25, 2024

The Malthusian Controller



There are lots of versions of the Malthusian Model. Understanding the model, which is very simple (see the directed graph, DG, above) is complicated by all the verbal expositions and criticisms of the model (Marx called it a "stain on the human race"). The model basically says that if the means of subsistence (production, Q, in the DG) does not expand as rapidly as population (N, in the graph above) then the Standard of Living (S) will decrease eventually creating a Malthusian Crisis.

From the standpoint of World-Systems Theory and Cybernetics, the Standard of Living (S) is the Malthusian Controller that keeps population growth in check. Although populations in Western Core Countries have had little or no experience with Malthusian Crises, the Malthusian model is still applicable to historical situations and may, in the future, become applicable to Western societies if Climate Change reduces Q.


The problem with the Classical Malthusian model is that there is no feedback between S and population growth (N). The original model was just two separate equations, one for population (exponential) and one for agricultural production (linear). The possible reactions to the (impending) crisis (positive and negative checks on population growth, what we now recognize as feedback) were not modeled. We can be charitable and forgive Parson Malthus (1766-1834) for not inventing Systems Theory, which was not invented until the 20th Century.

You can run R-code to experiment with the Malthusian Systems Model (with feedback) here and produce the time series plot above with shock decomposition. The model is taken from Germany after Unification in 1871 when there was a brief Malthusian crisis.

Notice that after 1890, a Malthusian Equilibrium is reached when population and production are in balance.