Fun fact; Det finns viss data pĂ„ âaktieutvecklingâ för enstaka bolag frĂ„n och med 1500-talets Frankrike upp till 1940-talet 
Episode 248: Prof. William Goetzmann: Learning from Financial Market History â Rational Reminder
VĂ€ldigt intressantâŠ
William Goetzmann: We have good measurements of the returns to shareholders from about the middle of the 1500s, and early 1500s. Those things, for at least one of the companies, go all the way up into the 1940s. So, that was very exciting to see.
William Goetzmann: Okay, so weâve studied one company that stretched the whole time period, it was about 5% real returns between 4% and 5%, on top of inflation. So, thatâs not too far different than what the US has experienced over the last couple of 100 years.
Now, sometimes the stock markets go up faster than that, 5% or 6% per year, inflation-adjusted. And then, sometimes you run into periods like a whole decade, where thereâs no return at all, on average. Thatâs the variation. But the 5% real return for an equity investment is surprisingly modern, even though it comes from looking at this ancient company that lasted over centuries.
Cameron Passmore: How much of an issue is survivorship bias in the very long-term historical data?
William Goetzmann: Well, I will say this company disappeared in the late 1940s. So, it didnât survive. But it did survive over centuries. There are a lot of â well, there are a few other corporations that when they began to appear, then they also eventually disappeared. The Dutch East India Company, for example, is a company that was braided to trade with the Spice Islands in Southeast Asia. And that lasted for quite a bit of time and then disappeared.
In general, companies have a lifespan. We have to imagine an investment approach that doesnât just hold one company from beginning to end, but basically invests in a portfolio of companies as they appear, and then just lives with the fact that they could also go bankrupt and so forth.
So, when weâre thinking about the equity premium, we typically imagine an evolving portfolio of companies, theyâre capturing the growth at any given time of the economy.