The UN Sustainable Development Goals agreed globally in 2015 include, for the first time, a target to reduce illicit financial flows.Three years later, the process to establish one or more indicators for this target is still ongoing. Illicit financial flows are, by their very nature, deliberately hidden - and so we rely on estimates using a range of methodologies and data.

As yet, there is no agreement on which are most robust and reliable estimates for policy or research purposes. And so this project is designed to produce a guide to the various types of illicit financial flows and a critical evaluation of the existing estimates. We hope it will prove useful for policymakers, academics and students, activists, journalists and all others with an interest in the area, and in better estimates.

Finding hard data on illicit flows, or components such as offshore tax evasion, has always been difficult. Ten years ago, even the data set on the tax take of countries around the world was so poor it was barely usable.

In that time we have made some progress. The ICTD-WIDER Government Revenue Dataset, for example, represents a major step forward in the quality and consistency of data on tax revenues. In 2012 the Tax Justice Network published The Price of Offshore, authored by Jim Henry, a former chief economist at McKinsey. That estimated that there were $11.5 trillion in assets held offshore. An update to that study in 2014 revised that figure to$21-35 trillion. @AlexCobham has been publishing work on the impact of profit shifting by multinationals on economies around the world, and in 2017 published one of the first impact studies to show the effect of profit shifting by US multinationals on individual lower-income countries' revenues.

One of our goals at the Tax Justice Network is to expand the knowledge base on the impact of 'tax havens' and the financial secrecy they provide - secrecy which is key to the continuing problem of illicit financial flows. We also want to make our research (and data) open, contributing to the global commons and allowing researchers and journalists access to a comprehensive set of research papers and datasets for their work.

To that end, we are launching here a project to create a new, collaborative, online book that seeks to provide a comprehensive picture of illicit financial flows. And we want you, and anyone else with an interest to be able to contribute to it.

To achieve this, we are going to be authoring our book on github, the open source repository and version control system for software developers. Although built to author software code, the platform is flexible enough to write a book on it. It also allows anyone to set up an account, comment on parts of the text, debate changes, contribute corrections or even entire new chapters.

The journey we are about to embark on is a bit of an unknown. Using collaborative tools to author a book has been done before. For example, one group of _hundreds _of maths professors created a book between them - but nothing like that has been attempted in the tax justice space.

There follows a brief guide to how to use github to contribute to this project. If you want to talk to us directly, you can email book@taxjustice.net.

One important thing to flag up: the intention is that this book will be published, and therefore please do read the authorship and accreditation section below.

We look forward to the collaboration!

# Using Github

There are several ways you can use github to participate in the project - all via here: https://github.com/Tax-Justice-Network/book

If you want to make a general comment, or would like to discuss an idea you have to contribute to the project, the first and easiest thing to do is to open up an issue. To do this click on the issue tab and then click “new issue”. A text editor will open up where you can leave a message, which will then be responded to.

## Editing

Github handles editing in a particular way. It is a little bit of a learning curve, but it provides an excellent way of handling edits from a variety of sources.

To edit a document you need to create your own working copy of the document. This is called a branch.

To do this you click on the button which says 'branch' in the code tab. Then enter a branch name into the text box that will appear.

Once you start working on the branch and you are ready to save your changes, hit commit. Each commit has a box which allows you to explain the changes you are making.

When you are ready to submit your changes, you submit a pull request. The pull request asks the editors to pull in your changes to the master copy. Pull requests can be commented on so that you can continue working on the branch at the suggestion of editors before the request is approved.

## Writing in github

Github uses a special type of formatting called Markdown, which we hear is wonderfully easy to use, and once you get the hang of it you will see that it will speed up your writing. You may even choose to start using it in your other work. Markdown is a way of marking text with extremely simple codes to signify headings, footnotes, bold text and so on.

A cheatsheet for markdown formatting is available here: https://guides.github.com/pdfs/markdown-cheatsheet-online.pdf

One markup feature which isn't mentioned is how to create a footnote. This is done with a marker in your text like this: [^1] and then a corresponding note at the bottom of your text like this: [^1]:this is a footnote

Github was designed for computer code and so the default editor is a code editor. This isn’t always great for writing long texts.

For that reason, you may want to try out http://prose.io – prose.io works in your browser and sits on top of your github account to create a more pleasant writing environment.

# Authorship

Once completed, we intend to publish this book as a physical, paper book. The book will (we hope) generate royalties which will be retained by the Tax Justice Network to continue working for global progress. By contributing to this work you should be comfortable with this idea. No individual will gain from any (potential) profits from this book.

We will list every contributor. Minor contributors will be thanked with an acknowledgement, major contributors will be invited to become co-authors of chapters.

Decisions on co-authorship will be taken by the editors @alexcobham and @petr_jansky.