Sick model
WA sick leave is 9 days. 2022 has 249 working days. Your chances of being sick (according to WA sick leave) are ~4% any given (working) day.
You have a partner. They also can get sick. Let’s say, if your partner gets sick, 75% chance you’re getting sick, too (and vice versa). You could be sick now ~6% of the time (on working days).
You and partner reproduce — hurray! — it’s 85% chance you’re getting what the kiddo is getting. (And even though kiddos are not employable, we still follow WA sick leave policy.) Your chances are ~10% now of being sick on any given (working) day. (We’re ignoring for a sec here that kiddo can get your partner sick, then you.)
Kiddo grows up, goes to preschool. There are 20 other kiddos in there, each of whom can get sick. Let’s be generous and say there’s 50% chance of your offspring getting whatever the preschool is having. Where does that put you? 13%
Aww, you just had a second kid! You think the innocent one has only 9 sick days a year per WA? Nope, he’s getting whatever his brother’s having, 90% of the time, too. What’s your chances of getting sick now? 22%
Twenty two percent chance of being sick on any given working day. That’s one day a week.
My calculations are most probably wrong. They sure feel right though in terms of work/life interruptions because —surprise, surprise—even if it’s not you being sick, you’re still the one taking the hit re: childcare.