Docs

- Minsky is an Open-Source system dynamics program.

Figure 7 shows Minsky’s interface.

Minsky’s major components, including Godley Tables (in two formats, widget and tabular view) parameters, variables, stocks and integrals are shown in Figure 12. Parameters, constants and mathematical operators are shown

Minsky supports many mathematical operators, from the familiar add (+) , subtract (−) , multiply (×) and divide (/) , through trigonometric relations ( ) to operators for tensor mathematics (dot products, inner products,

As you build a model in Minsky, it generates a catalog of the entities in that model, which you can assess directly by the Browser window. To bring it up, click on the widget and then choose Browser . Figure 16 shows the

Godley Tables were primarily designed to enable the easy modelling of monetary dynamics. The examples in this chapter focus on the macroeconomics of money, but Godley Tables can be used to model the internal accounting o

Unlike the majority of system dynamics programs, Minsky enables the simulation itself to be dynamic: graphs are updated dynamically, and the model’s parameters can be varied as a simulation runs to see what happens. This

The model in Figure 27 is not quite complete, because it shows the system from the banking sector’s perspective, but not their customers perspective—the “Non-Bank Public”. This is easily corrected by adding another Godle

The standard system dynamics paradigm is a flowchart: flow inputs are aggregated into a stock, with wires connecting the flows and the stocks. Minsky supports this paradigm as well, but with a few differences to the indu

The models shown here to date are quite small, and easy to navigate on a single PC screen— especially with judicious use of the Zoom “magnifying glasses” on the control bar. But Minsky can support enormous models which a

Another way to organize a model is to place subsets of the model into Groups. Minsky supports grouping, but there are limitations in our current implementation of it: firstly, grouped variables are local to the group; se

There are five main sources of help on using Minsky:

Minsky relies upon a community of users who help identify problems with the program, and suggest ways in which it can be improved. We encourage any Minsky user to join at least one of two Minsky groups via SourceForge:

Ravel is a new, entirely visual, “no-code” way of analysing any type of data. Broadly speaking, today there are 3 types of computer programs used for data analysis:

We will use economic data in this tutorial, since there are easily accessible and publicly available economic databases. But Ravel can handle data on any topic, from marketing to palaeontology. Here are four examples.

You place objects on the canvas by clicking on the relevant icon in the widget bar (and its submenus, which pop out above and to the right of widgets when needed), and then clicking where you wish to place them on the ca

The basic entity in a spreadsheet is the cell, and data analysis in a spreadsheet requires the use of cell reference formulas. It’s easy to write simple formulas in a spreadsheet, but the task becomes unwieldy with compl

The BIS database on house prices has twelve dimensions, most of which are superfluous; these were reduced using the data import procedures explained later in this tutorial, to leave just four significant dimensions:

Often you will wish to work with only a summarized form of a dimension. That is done by “collapsing” or “rolling up” an axis towards the centre of the Ravel.

Variables should have meaningful names, so that it’s easy for yourself and others to understand your analysis. Ravel uses the LaTeX text formatting language to enable users to create very informative variable names: Engl

The BIS is 2010, so all indices are 100 during 2010), and the annual rate of change of house prices, with data on both Nominal and Real (CPI-deflated) prices. To analyse the data, it is useful to separate it into House P

Figure 32 shows the result of doing this. Firstly, select just the data for "Advanced Economies" using the selector dot, and attach that to a new variable ∆ HPIAdvanced__Avg .

Figure 34 shows a Ravel attached to a Sheet and a Plot, with selections made on two of the Ravel’s 4 axes, so that the output is 2-dimensional: Country by Date, with Date being the x-axis for the Plot and the row entries

Ravel has a large number of mathematical operators which are accessed via the widget bar. The top-level menu items are shown in Figure 40.

Ravel can import data from numerous sources into one file, which enables easy analysis of the relationships between the data, using their shared dimensions.

Thus far we have used Ravel to explore existing data. But there can also be hypothetical data, as in breakeven analysis for sales planning: given estimated costs of production, at what level of

Ravel supports a range of statistical functions (the range will expand significantly in future releases), the widgets for which are on the menu, and are explained in Table 6. The relationship between change in household

There are two main ways to display your results in Ravel: Plots and Sheets .

The Ravel wiring canvas is essentially unlimited, which means you need tools to organise and navigate it as your model grows. Ravel provides two main tools for this:

Ravel’s text tool enables you to place text anywhere on the wiring canvas. There are two ways to enter text:

Ravel models are far easier to audit and understand than spreadsheet models, where fundamentally only the person who designs a sheet can understand the logic contained in its cell reference formulas. In contrast, anyone

Publication Tabs let you show the results of your calculations, without necessarily showing the workings behind them. Items on the Wiring canvas can be placed on a Publication Tab via—you guessed it!—the right-click menu

Ravel can export any canvas to a number of other file formats, using the “File/Export Canvas as…” command.

Any data can be loaded into a spreadsheet, because the rows and columns in a spreadsheet are just placeholders. Ravel is pickier, since its dimensions—the equivalent of a spreadsheet’s rows and columns—specify a unique p

All Ravel objects have either a single arrow, or an arrow on each corner, which can be used to resize the object. Click and drag on any object to alter its size.

Ravel has a context-sensitive help system. For help on any aspect of Ravel , hover over the relevant operator and choose Help from the context menu.

Currently Ravel is being distributed via the Patreon page www.patreon.com/Ravelation. If you sign up to this page for US$7 per month, you will have access to the online store (and also posts containing new releases of Ra

I closed The New Economics: A Manifesto (Keen 2021) with an observation on the following remark by John Blatt in his brilliant book Dynamic Economic Systems (Blatt 1983):

Technically, this book is a free companion to The New Economics: A Manifesto (Keen 2021)— hereinafter referred to as Manifesto —with two main functions:

To install Minsky on a Windows PC, double click on the MSI (“MicroSoft Installer”) file that you have downloaded from SourceForge. This will bring up the dialog box shown in Figure 1.

This is a very technical book, for the simple reason that it explains how to build economic models using a mathematical program. But you can do a lot with Minsky without having to create a mathematical model, because man

Figure 58 shows how Minsky appears when you first run the program.

The Wikipedia defines system dynamics as “an approach to understanding the nonlinear behavior of complex systems over time using stocks, flows, internal feedback loops, table functions and time delays”, and “a methodolog

Minsky ’s double-entry bookkeeping tables are named after Wynne Godley, for three reasons:

My main motivation for inventing Minsky was to enable proper modelling of money. Since then, Modern Monetary Theory ( MMT ) has risen to prominence, and Minsky is ideally suited to analyzing the claims and counter-claims

Lotka’s model was easily derived, simply by acknowledging that sharks eat fish, and by using the simplest possible mathematical operation to link the two species together.[68] It’s also easily analyzed, since with just t

The work in this chapter is the most technically demanding in this book, and also the area most needing follow-up work … by people like you! As I note in Manifesto , the fact that economics has persisted for almost a cen

This should not be is a difficult chapter, because it is telling you how to do something that you should already know how to do : to work out the qualitative properties of a dynamic system.

The science fiction author Ray Cummings once wrote[109] that “time is what keeps everything from happening at once”. Time, or the lack of it, is also what keeps some things from happening at all. In my case, the lack of

I hope that the preceding chapters give you a reasonable introduction to modelling in Minsky , as well as an explanation of why continuous time system dynamics modelling is an excellent foundation for a monetary, far-fro

This is an extract from an as yet unpublished paper undertaken with Paul Ormerod and Nyman Rickard.

References