I dont understand the meaning of mach assumptions. Would be helpful if you could help me understand using an example or put the same thing in more easier terms. The key assumptions are that: • the run-off pattern is the same for each origin period (as for the chain ladder) • the future development of a cohort is independent of historical factors (eg high factors in one period do not imply high or low factors in the following period) • the variance of the cumulative claims to development time t is proportional to the cumulative claims amount to time t - 1.
