ex.dt.bad {poisFErobust}

Poisson data violating conditional mean assumption

Description

A data.table containing id by day observations of Poisson random variables which violate the conditional mean assumption of Wooldridge (1999).

Usage

data("ex.dt.bad")

Format

A data.table with 450 observations on the following 7 variables.

id

a factor with levels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

day

a numeric vector

fe

a numeric vector

x1

a numeric vector

x2

a numeric vector

y

a numeric vector

x1.lead

a numeric vector

Details

The data were simulated like y <- rpois(1, exp(fe + x1 + x2 + 2.5*x1.lead)) where fe, x1, and x2 are standard normal random variables. fe varies only across id. x1.lead is a one period lead of x1 which causes the violation of the conditional mean assumption.

References

Wooldridge, Jeffrey M. (1999): "Distribution-free estimation of some nonlinear panel data models," Journal of Econometrics, 90, 77-97.

Examples

data("ex.dt.bad")
str(ex.dt.bad)