Before revision:  We use the standard model of noisy exponential growth and compute time-average growth rates instead of expectation values of wealth . In this new paradigm insurance contracts exist that are beneficial for both parties .
After revision:  We use the standard model of noisy exponential growth and compute time-average growth rate of wealth. Our solution assumes only knowledge of wealth dynamics. Time averages and expectation values differ because wealth changes are non-ergodic. Our reasoning is generalisable: business happens when both parties grow faster .