That depends on the difficult of what they're developing. Boilerplate code? Two great programmers are a waste. Moderate difficulty? Maybe less efficient than

That depends on the difficult of what they're developing. Boilerplate code? Two great programmers are a waste. Moderate difficulty? Maybe less efficient than working separately, but they'll still work a bit faster, produce fewer defects, transfer knowledge well, etc. Really complex problem? Not a waste at all.