OK who wants a thread on why gangs rule? Not why gangs are great. I mean, when and how do they govern civilians.

Here we are meeting one gang leader who, besides running the drug trade, has built this crafts school behind him, a recycling center, and a community pool.

This isn't a slum. It's a middle income neighborhood in Medellin, Colombia. Nearly every low- and middle income neighborhood in the city has a resident gang called a combo.

We spent 4 years interviewing dozens of members and leaders of 31 criminal groups.

Here's a map of the city. We also surveyed 7000 people on what services state and combos provide. Medium & dark red indicate a combo intervenes in disputes, crime, and disorder more than the state.

(By we I mean @SantiagoTobon @BigBigBLessing & @gusduncan with @poverty_action)

This is surprising because most combo members look like this. Are these the guys you want guarding your street or handling noise complaints? But the young guys run drug corners. The older savvy ones have the "relacionista" position, collecting extortion & helping the community.

Not all combos govern. It's a choice. In part a business line. Govern more, charge more. Extortion or taxes?

Now, you'd think that combos arose and governed where the state was absent, ineffective, or corrupt. But the first thing you need to know is that communities with more state governance also have more combo governance, even after you account for income, demographics, terrain...

What gives? Probably some third unobserved force or characteristic makes some neighborhoods well governed in general, right? No way this is causal.

So we first look at a border discontinuity, looking at what happens to state and combo governance levels on your block when you cross a border to a nearly identical block, and your proximity to your police and municipal headquarters drops by 500m.

Then we work with the city to run what I think might be the first gang-level randomized trial ever run. The city sends representatives into dozens of neighborhoods for 2 years to govern the heck out of them. Crowd out gang rule.

Nothing is as expected. State rule does not crowd out gang rule. If anything, the opposite occurs!

If you want to learn more, and why, you will have to tune in.

Live presentation on Friday Oct 2: https://twitter.com/poverty_action/status/1310675167639744520?s=20

Meanwhile, if you want to see some real time fieldwork tweets, here is a thread from earlier this year. https://twitter.com/cblatts/status/1221141762099613697?s=20

Mil gracias a
@JuanPabloMesaM
@MAranzazuRU
@David_Cerero
@PeterDeffebach
@SebastianANicol
@so7fia
@AngieMondragonm
@montoyacaler0
@EAFIT
@poverty_action
+ the Twitter-challenged Felipe Martinez and Zach Tausanovitch

Paper should be out in the next few weeks. Stay tuned...

Including (for the curious) details of THE most comprehensive & exhaustive human subjects precautions I've ever taken (and I've done some). Everything from presenting to the IRB committee in person (a first for me) and involving justice minister, head of prison system, & Mayor.

Also an explanation for why I can only write one freaking paper a year.