In about 2011, feeding my insatiable need for podcasts, I came across a fascinating one by Toby Ord. He asked a question that caught my attention: if we want to make the biggest possible difference to the world, what is worth more: our time, or our money?

Because of charities like the Schistosomiasis Control Initiative (SCI), doing so much good per dollar donated, his answer was money. Toby Ord seemed to be saying that volunteering for virtually any cause or charity could not possibly do as much good as just earning money – for the same number of hours of work – and then giving it to SCI to deworm children.

His argument was very persuasive. If I decided to pledge 10% of my future income to these highly cost-effective charities, this decision would almost certainly cause more good than any other action I could ever take in my life, by far.

But what Toby said at the end of his talk had even more influence on me. He said:

I thought that my time spent volunteering could never be worth as much as my donated salary. But then I realised that by setting up this organisation and publicising these ideas and so forth, I could have much larger impact because … [there] is actually a multiplier effect, getting other people to try doing the same thing … I had already raised more money over the last year than my entire future income. So time can, in some cases, be worth more than money.

Mental arithmetic told me that, if I persuaded just one other person to take the pledge, I'd double my impact on the world. And if I could persuade one more person each year for the rest of my life, I'd increase my impact about 50-fold. That, it seemed to me, was the way to go about it.

So I decided to start a chapter at my university. For two years I tried all sorts of things. Finally one got started in Belfast and I also got involved setting one up at Glasgow. Both these chapters are successes, run by enthusiastic, energetic volunteers packing in event after event. Huge credit has to go to Beth Malcolmson, Kevin McNicholl, Sinead O'Gara and Carla Ní Chéarnaígh in Belfast, and Irene Tortajada Querol, Anna Viceconti, Lovisa Jakobsson and Bradley Ford in Glasgow, for the incredible work they've done running those chapters.

Setting up a new chapter has the potential to be very high-impact. About half of volunteers in Glasgow and Belfast hadn't heard of effective altruism before, and most have said they'll pledge 10% of their income when they begin full time work. It's also great fun and will grace any CV. Now I'd like to give my advice on setting one up, in the hope that it might inspire and help you to do so.

A roadmap to setting up a chapter

Step one: spread the word

Let as many people as possible know that you are trying to start up a chapter. Social media (Facebook, Twitter) and emails are an easy place to start. For instance, start a Facebook page and join as many local groups as possible. Then post in those groups "Here is a page you might be interested in: stay up to date on cost-effective ways to end global poverty," with a link to the page. You might get about 100 likes; you can then post to that page about setting up the chapter and inviting people to help out. Asking academics or schools to send out emails about the new chapter is also a very good way to reach potential comrades.

10-15 are likely to get in touch with you following all this. Make good links with these people. Reply quickly and reliably. Befriend people on Facebook. Above all, try to meet up face-to-face or by video call. From 10-15 people, 2-3 might be enthusiastic enough to form the core group of the chapter. That's all you need.

Step two: run an event

You can even try this by yourself, as a way of spreading the word and attracting members. Setting up an event can appear daunting at first. But once a venue is sourced, and a speaker obtained (for a lecture event), the bulk of the work is promoting it: the whole thing can be done with less than eight hours work. Promotion is the key and much can be done via social media: posting on Facebook, Twitter, and mailing lists. Lecture shout-outs and putting posters around campus can also help. For a first event, collaborating with an existing society (for instance, Students for Global Health — formerly Medsin can ensure a crowd.

Step three: keep it going

At each event the main aim is to encourage more people to join the mailing list, to tell people about the pledge and about effective giving, and to encourage people both come to future events and help run the society. Be approachable and easily contacted. Above all, if people express an interest, get them involved and encourage all and any ideas.

As an indication of what kind of events you can run, Belfast have had Alan Fenwick of SCI speak, and will host Peter Singer for a video conference soon. There is a debate and a concert planned. Glasgow obtained a huge audience for Peter Singer and ran a highly successful charity pub crawl amongst other events.

Setting up a new chapter is, I believe, as simple as it seems. It needn't be hugely time-consuming. An event can take as little as six hours to prepare for (including promotion). 20-30 hours work over a period of several months, or roughly an hour or two a week, can be sufficient to set up a sustainable and vibrant chapter.

Step zero: ask us for help

Jonathan Courtney (the Director of Outreach at Giving What We Can) and I believe that chapters are extremely important and we want to help new chapters as much as possible. To this end we are trialling a mentoring scheme: someone experienced in running a chapter will give hands-on help for up to a year or more. So if you are interested in starting a new chapter, contact me or Jonathan and we'll help you get started.

You may fear there isn't sufficient interest in your local area to sustain a chapter. But with this enterprise taking just an hour or two a week for a few months and with the potential gains so high, it is worth the risk, no matter where you are. Nor will you be alone; contact us and let us help.

Erwan Atcheson: belfast@givingwhatwecan.org

Jonathan Courtney: jonathan.courtney@givingwhatwecan.org