Both tests building up on the two probits
and the bivariate probit
reject the null hypothesis of conditional independence at a significance level of [alpha] = 0.
It should be noted that because the cut-off points in the ordered probits
are not significant.
Nonetheless, because only a third of the sample needed to see a specialist and bivariate probits
required estimating more than twice as many parameters, there was insufficient power to detect differences.
The main weakness of the analysis is that some of the techniques, such as the bivariate probits
, 2SLS, and fixed effects models, produced imprecisely measured estimates.
To investigate whether families increase hours enough to qualify for this In-Work payment, we ran selection-corrected probits
for the probability of meeting the hours threshold separately for partnered and unpartnered women.
Table A1 reports the mapping between the underlying categorical responses, the standardized categorical responses, and our scaling derived from these ordered probits
After correction, the percentages were converted into probits
The actual sequence of transition probits
depends on the woman's history.
Results are generally similar for cross-sectional probits
and specifications including state dummy variables.
used for binary indicators and tobits for nonnegative continuous variables.
Therefore, in the first column, we present probit
estimates for high school completion and youthful alcohol consumption onset; these probits
were estimated based on the assumption that [rho] = 0, that is, there is no correlation between the unobserved error terms.
One should note that while we think this method of estimating child care costs has substantial benefits over alternatives such as average child care costs in the location of residence (which is not available with SIPP data), because of its acknowledgment of differences in the probability of paying for care, the disadvantage is that bivariate probits
are in general quite sensitive to sample size.