A more interesting question is whether or not TDD leads to better design or not. Even if TDD doesn't change the difficult of good design, it can empirically aff

A more interesting question is whether or not TDD leads to better design or not. Even if TDD doesn't change the difficult of good design, it can empirically affect the level of design. Here's a theoretical example of how that's possible: changing the design before tests are written and without using TDD requires less time than when using TDD. The reason (hypothetically) is simple: you need to rewrite tests more if you're using TDD. This might lead developers to redesign software slightly less on average if they're using TDD.