The Disagreement You Haven't Had Yet

I missed an issue.

The 1st of October came and went and The Letter didn't go out. First time in nearly three years.

I lost access to my email. My email also holds my multi-factor authentication, so one account going down took every other account with it! There's a multitude of lessons in this experience alone.

Three weeks ago I asked whether you could take three weeks off and still have the second and third contracts close. I lost one week and the letter stopped, which tells you where I sit on my own test. That prompted my own reflection - I have no co-founder. No second person to help when things don't go as planned. And nobody who could've pressed send.

I have started four companies and I have never once had a co-founder. That's been a choice every time, and the week I spent locked out is the strongest argument against it - so I went looking for the evidence.

The numbers are interesting.

Carta's 2025 data shows solo founders were 23.7% of new startups in 2019 and 36.3% in the first half of this year. More of us every year. In 2024, solo-led companies made up 30% of startups founded and took 14.7% of the cash raised in priced equity rounds. A third of the companies. A seventh of the money.

On whether the money is right, the research says something different. Greenberg at NYU Stern and Mollick at Wharton tracked 3,526 ventures and found solo founders were 55% less likely to dissolve the business than teams of three, with for-profit solo ventures around two and a half times more likely to survive. Their sample was crowdfunded companies rather than venture-backed ones, so hold it loosely. It is still the clearest thing anyone has published.

And here is what I could not find. There is no current figure for how often co-founder relationships break. The one everybody quotes, that 65% of startups fail because of founder conflict, is from Noam Wasserman's work at Harvard, published in 2012. Fourteen years old. Every article citing it is citing him. Nobody has gone back and measured it since.

I have said for years that going into business with someone is like a marriage. Everybody reaches for that comparison and it holds for the most part, the connected nature, the money, the difficulty of leaving. Where it stops being useful is this - People entering a marriage have usually spent years disagreeing with each other first. Most co-founders incorporate within months of meeting.

So before you incorporate with anyone, there is a better question than whether you get on.

Have the two of you ever had a serious disagreement, about something that mattered, and come out the other side still working together? If the answer is no, you don't know that the partnership works. You only know it has not been tested.

Three things are worth settling in writing while everyone is still delighted with each other. How long each of you intends to be here. What each of you would do if an offer arrived at a number one of you thought was enough. And who decides when you cannot agree, because somebody has to, and choosing that person is far easier before you hit turbulence, than during.

Reply and tell me which way you would do it next time, solo or with someone. I would like to know.

Back on the 15th, on time.

With purpose,

Sara