Difference between revisions of "Dynamic Input-Output Models"

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== Formula  ==
 
== Formula  ==
 
The typical equations of the dynamic input-output model:
 
The typical equations of the dynamic input-output model:
* X = AX + C + Dt
+
* X = A X + C + Dt
* D = BX - BXt t+1 t
+
* D = B X - B Xt t+1 t
* Xt = AXt + Ct + BXt + 1 - BXt
+
* Xt = A Xt + Ct + BXt + 1 - BXt
* (I A + B) Xt = Ct + BX
+
* (I - A + B) Xt = Ct + BX
  
  
 
The production of period t is defined:
 
The production of period t is defined:
* X = (I A + B)-1 (C + BX )
+
* X = (I - A + B)-1 (C + BX )
  
  
 
while the production of period t+1 is determined by:
 
while the production of period t+1 is determined by:
* X =B-1[(I A + B)X - C ]
+
* X =B-1[(I - A + B)X - C ]
  
  
 
Where:
 
Where:
* Y = final demand
+
* Y = [[Final Demand]]
 
* I = unit matrix
 
* I = unit matrix
 
* A = input coefficients for intermediates
 
* A = input coefficients for intermediates
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== Issues and Challenges ==
 
== Issues and Challenges ==
Practical problems relate to the matrix B of capital coefficients.
+
* Practical problems relate to the matrix B of capital coefficients.
 +
 
 +
== Further Resources ==
 +
* [https://www.openriskacademy.com/mod/page/view.php?id=800 Crash Course on Input-Output Model Mathematics]
  
 
== References ==
 
== References ==

Revision as of 13:17, 18 September 2023

Definition

Dynamic Input-Output Models is a category of various possible generalization of the basic Input-Output Model that allow accounting for more sophisticated temporal behavior[1]

Formula

The typical equations of the dynamic input-output model:

  • X = A X + C + Dt
  • D = B X - B Xt t+1 t
  • Xt = A Xt + Ct + BXt + 1 - BXt
  • (I - A + B) Xt = Ct + BX


The production of period t is defined:

  • X = (I - A + B)-1 (C + BX )


while the production of period t+1 is determined by:

  • X =B-1[(I - A + B)X - C ]


Where:

  • Y = Final Demand
  • I = unit matrix
  • A = input coefficients for intermediates
  • (I-A)-1 = matrix of cumulative input coefficients (inverse)
  • B = input coefficients for capital
  • C = exogenous final demand (consumption)
  • D = induced investment
  • T = time index


This is a system of linear difference equations, since the values of the variables are related to different periods of time. Consumption is expected to grow at the annual rate (1+m)t.

Issues and Challenges

  • Practical problems relate to the matrix B of capital coefficients.

Further Resources

References

  1. Eurostat Manual of Supply, Use and Input-Output Tables, 2008 edition