Robust design SE = 0 or near to that

[Rosvita]

I am running de robust design to get population size estimation.
However, the standard error is 0 or very, very small (Ex: 0.2829073E-14). Does anyone know what the problem could be? Is there a problem with my data?
Thank you very much!

Rosvita

[gwhite]

You almost certainly have run a model without putting a constraint on the last p value, so that it is estimated as 1, and Nhat = M(t+1). That is, the population estimate is equal to the number of animals captured.

The p for the last occasion is not estimable without setting it equal to something else. The art of building models for the closed captures data type is determining how to constrain this last p and still capturing the variation in the encounter histories.

Gary