The plus of Kim's study is that he employed Orchard Village as a comparison (although he did not control for any demographic differences); the minus is that his results were likely confounded by selection effects
(that is, Kentlands marketing attracted more social and civic residents and Orchard Village probably attracted a far less civic mix) and concentration effects (it was easier to socialize with others since the random Kentlands resident was more social).
H3: After correcting for HRM and selection effects
, the elasticity of training is positively related with firm size.
Many studies which attempt to demonstrate the effect of moving out of, or into, employment produce results that are ambiguous because of the difficulty in ruling out selection effects
As noted, both Stam (1996) and Lake (1992), while failing to control for selection effects
, found that democracies are more likely to win.
In addition to learning just how minimally effective these programs were, we are reminded (if we ever knew them) of critical principles of evaluation design, such as selection effects
, maturation effects, and regression to the mean (less a statistical notion than a behavioral one).
in press), total fitness is a power function of the individual selection coefficients, but that changes the selection effects
of even single mutations.
And further, depending on the efficiency of the selection effects
, and the efficacy of deferred wage schema, some defined-benefit firms can have zero quit rates; others positive but small quit rates.
These univariate tests may not sufficiently differentiate increased adverse selection effects
on the spread from the effects of simultaneously higher liquidity in target shares.
Table 4 shows the regression outputs and Table 5 collates behavioral difference, learning and selection effects
, in which learning among economics majors is tested using Wald test.
This is by no means representative of the population at large, but if anything it is more homogeneous--making it more difficult for us to observe selection effects
within that group.
As I argued in my review of the book Crossing the Finish Line by William Bowen, Matthew Chingos, and Michael McPherson (Spring 2010), the central problem in educational lay not be policy research is disentangling selection effects
from program effects in educational outcomes.
We assess ecological spillover effects from MMC directly, by including MMC penetration as an explanatory variable, along with other statistical control variables needed to reduce potential selection effects
that might impact the MMC spillovers estimate.