Table 2

Segmented regression models evaluating the sex ratio and changes therein during the following three intervals: before election (from April 2010 to October 2016) (segment 1); the period from election to before the anticipated effect (from November 2016 to February 2017) (segment 2); and the period from the anticipated effect to 5 months thereafter (from March 2017 to July 2017) (segment 3), respectively. Data are shown for the entire population of Ontario, the population in politically liberal-leaning regions at the time of the election, and the population in politically conservative-leaning regions at the time of the election, respectively

Segment 1:
before election (April 2010–October 2016)
Segment 2:
from election to before effect (November 2016–February 2017)
Segment 3:
from effect to 5 months thereafter
(March 2017–July 2017)
Baseline level of sex ratio before electionBaseline level of change in sex ratio before electionDifference in
sex ratio compared with pre-election
Difference in change in sex ratio compared with pre-electionDifference in sex ratio
compared with
before effect
Difference in change in sex ratio compared with before effect
β0p valueβ1p valueβ2p valueβ3p valueβ4p valueβ5p value
Entire population1.0603<0.0001−0.0001310.0920.01950.11−0.0014640.36−0.04480.020.01330.01
Liberal-leaning regions1.0605<0.0001−0.0001330.0960.01510.22−0.0007260.66−0.05390.0060.01730.002
Conservative-leaning regions1.0591<0.0001−0.0000670.76−0.0320.350.0005850.90.08230.12−0.01030.49
  • Notes about interpretation of level of sex ratio and change in sex ratio: β0 estimates the level of the sex ratio before the election (baseline level). β0+β2 estimates the level of the sex ratio after the election but before the anticipated effect occurred. β0+β2+β4 estimates the level of the sex ratio from the anticipated effect to 5 months thereafter (predicted duration). β2=(β0+β2)−β0 estimates the difference in sex ratio between after the election but before the anticipated effect occurred (segment 2) and before the election (segment 1). β4=(β0+β2+β4)–(β0+β2) estimates the difference in sex ratio between the time period from the anticipated effect to 5 months thereafter (segment 3) and the time period after the election but before the anticipated effect occurred (segment 2). β1 estimates the change in the sex ratio before the election. β1+β3 estimates the change in the sex ratio after the election but before the anticipated effect occurred. β1+β3+β5 estimates the change in the sex ratio from the anticipated effect to 5 months thereafter (predicted duration). β3=(β1+β3)−β1 estimates the difference in change in sex ratio between after the election but before the anticipated effect occurred (segment 2) and before the election (segment 1). β5=(β1+β3+β5)–(β1+β3) estimates the difference in change in sex ratio between the time period from the anticipated effect to 5 months thereafter (segment 3) and the time period after the election but before the anticipated effect occurred (segment 2).