That is a good question. Wonder ... how would you measure the effectiveness of TDD? Think about that for a while... I'll go get the research papers...Did you come up with a few effective measures? Are they pratical - or - cost prohibitive?Why not just use your own subjective judgement...

Let's start with your life span... it starts some 20 - 70 years ago. So some of us have seen the first computers used in our area (state, city, office building) - while others of us have grown up in the "new millennial age" always having a screen in front of them. So that gives our sample a great depth of experience. Now think about the first several computer you can remember interacting with... how often did it crash - lock up - shutdown - reboot? Compare that frequence to the device you have in your pocket - OK. I'm making an educated guess - some time ago was way worse than today.Now shift focus - when did TDD start out in the minds of just a few people and start to spread to the rest of the computer world? That time frame could easily be found - but for the sake of not googleing it... let's say 1999. So TDD is 20 years old - and is now a common term in the industry - practiced... well, much more practiced today than in 2001 (A Space Odyssey) and more practiced today than 2010. Safe to say it has been on the increase and code quality - as experienced by people using computers in everything from a coffee maker to a nuclear power plant, has increased. Causation - or just Coorelation - or Neither? You tell me?Here's a great article - chapter - research of a meta analysis of TDD's effectiveness.

What can it say that is more convincing than your experience?

How Effective is Test-Driven Development?

Burak Turhan, Lucas Layman, Madeline Diep, Hakan Erdogmus, Forrest Shull

I ran across this Twitter thread... it looks really promising. Let's follow along.

https://twitter.com/ceilfors/status/1578324323160363008?s=20&t=vqVXhV7siLQHkYFpIcizOg by Wisen Tanasa @ceilfors