Beyond this basic set of controls, the only characteristics included in specification 1 are the dummy variables that are required for a DiD analysis.
Even though we are able to control for a large set of background characteristics in our specifications, if we are still omitting variables that explain maternal grandparental death and young women's labor force participation, IV estimates are likely to be biased.
Furthermore, the mechanical property of concrete that is designed or controlled is typically its compressive strength, since this is the most important material characteristic in concrete specification and in building codes (Li 2012).
The mechanical property of concrete that is designed or controlled is typically its compressive strength, since this is the most important material characteristic in concrete specification and in building codes.
This affects mainly the model or brand-segment dummies (it usually affects "irrelevant" dummies such as, for example, those that correspond to models that are not sold in the period), although in very specific time periods it may also affect some dummies for characteristics in the Fixed Effects specification (see Table 5 in the online appendix in supplementary material).
Finally, we restrict our sample to employees who stay with their employer in order to account for time-invariant, unobservable firm characteristics in fixed-effects specifications.
When including study characteristics (method and publication status) in specification 2, the results remain very similar.
My results are not driven by changes in maternal or city specific characteristics, and are robust to variations in specification and to the choice of control group.
In specification 4, sample characteristics enter the equation: participant gender (baseline: pooled estimation for men and women) and treatment in the 2000s (omitted: 1980s or 1990s).
When controlling for permanent family characteristics in the sibling-fixed effects specification, only father's YSM seems to matter for Math achievement.
