FREE Supply/Demand Charts That Illustrate Various Micro Economic Situations, Including Benefit Changes From Alternative Scenarios That You Can Generate (requires Excel with VBA macros)
These simple supply/demand charts only require Excel 2013 or later (but not VORSIM). In sets 1-5, Supply and Demand are fixed but prices can sometimes be changed to illustrate economic impacts. Elasticities are generally fixed.
SDgraph 1 World prices determine supply, demand and trade quantities for a product in a country. Change the world price for alternative scenarios.
SDgraph 2 World price + tariff determine supply, demand, imports. Change the world price and/or the tariff for alternative scenarios.
SDgraph 3 World price + export subsidy determine supply, demand, exports. Change world price and/or export subsidy for alternative scenarios.
SDgraph 4 Supply, demand – base and alternative scenarios. Shift supply and/or demand schedules to obtain alternative equilibrium situations. Benefits (surpluses) are calculated for scenarios as well as differences from the base scenario.
SDgraph 5 The impact of a monopoly (sole seller) situation is shown and benefit changes are calculated.
The supply/demand graphs below allow you to draw alternative scenarios by shifting the schedules. Shifts are made with leaving intercepts fixed for simplicity; for small shifts about the equilibrium, this is a reasonable approximation for the calculation of changes in benefits.
DrawMonopoly The impact of a monopoly (full or partial) is calculated for scenarios that can be generated.
DrawSDshift This chart shows the impact when supply/demand schedules are shifted by taxes or subsidies.
DrawShiftQSD This chart shows the impact when supply/demand schedules are shifted by quantity (percentages)
The remaining Supply/Demand schedule shifts the entire schedule (rather than rotate schedules around their intercepts as is done above.)
ShiftSD This chart rotates supply/demand schedules about the base equilibrium when elasticities are changed. Impacts of shifts can be calculated for different supply/demand elasticities. Elasticities for all of the linear schedules are centered on base equilibrium price and quantity and are used to calculate slopes of all these linear schedules.
Download VORSIM 16 for FREE!
FREE version of VORSIM 16 [requires Excel 2013 or 2016] – download, unzip, and run the *.exe files to install VORSIM 16. Demonstration models can be loaded below. You will have to adjust your security to the lowest levels to install VORSIM. Windows is cautious about VBA macros.
Click to download VORSIM 16 à VORSIM 16
Download Small Demonstration Models for VORSIM 16
LUMP – Small VORSIM model for learning the system
DEMO – Small dynamic trade model with constant elasticities
DEML – Small dynamic trade model with linear equations
DARM – Small dynamic trade model with Armington specification
STAT – Small static trade model with constant elasticities
Download large working models for VORSIM 16 by clicking on model name
NFAP - Dynamic National Food and Agriculture Policy model – 11 countries/regions (covering the world), 13 product groups, 60 years with 1991 base
SFAP - Static world Food and agriculture Policy model – 11 countries/regions, 13 product groups, 1991 (static version of NFAP)
SWOP – USDA SWOPSIM (Static WOrld Agricultural Policy simulation model) - 11 countries/regions, 22 product groups, 1986 base
ST89 - 11 countries/regions, 22 product groups, 1989 version of SWOP
You can download (by clicking the Situation button) these supply demand situations and change parameters to see how the results are changed. Alternatively, you can install all of the charts with the SDchartsetup program at the bottom of this column.
Consumer and producer benefits (surpluses) are used to measure the impact of policy or economic changes.
You can also download VORSIM 16 and learn with the demonstration model DEMO.
You can install all of the graphs by downloading SDchartsetup below:
These large world agricultural models will run in VORSIM 16.
The charts use versions of Excel that require the xlsx suffix (e.g. Excel 2013 or 1016).