If Brandon Johnson wants a better understanding of why Chicago businesses are chafing at the most onerous paid-time-off requirements in the nation, he need do no more than walk across to the Cook County side of City Hall and ask his political mentor, Cook County Board President Toni Preckwinkle.

The County Board late last year acted to strengthen a separate state law — which took effect Jan. 1 — requiring a minimum 40 hours of paid time off for any reason for full-time workers in Illinois.

Among other things, the county made the state law apply to airline workers, which the state exempted. And, as Chicago did last year, the county also gave affected employees in the suburbs the right to sue their employers if they felt they’d been shortchanged on paid leave. Employers who lose in court can be assessed triple damages with interest and forced to pay plaintiffs’ legal fees.

But the county also did something in December that subsequently has exposed the “rules for thee but not for me” nature of this issue. Although the state law exempted school districts and park districts, the Cook County version made those rules apply to such bodies within Cook County. The subsequent outcry from schools and parks officials prompted Preckwinkle on Jan. 25 to offer an amendment to (once again) exempt the schools and parks.

The arguments the school and parks officials made were familiar. The hastily passed ordinance could affect workers such as substitute teachers, camp counselors and lifeguards who arguably shouldn’t be earning paid time off, since they are seasonal or part time. It would cost the districts more money, which would mean higher fees for suburban users, since their property tax levies are capped.

Right. Busted budgets. Chicago’s paid-leave policy is far more onerous than the state’s (and the county’s) and has businesses within the city making exactly the same arguments.

But businesses don’t get the same sympathy from the Preckwinkles and Johnsons of the world that government officials do.

Memo to Johnson: As your political mentor now unwittingly has demonstrated to you, rules like the ones you pushed through the City Council in the face of staunch business opposition cost money. Unlike municipal officials, businesses can’t just raise taxes and fees to cover those costs. They either have to cut their own costs — such as payroll, which means fewer jobs — or raise their prices, which means higher prices for consumers. There’s no free lunch.

The irony on the county side is that the ordinance passed in December now appears extremely limited in practice, with park and school workers expected to be no longer covered. Effectively, it appears mainly to have added airline workers and some delivery employees that the state law exempted. And, arguably, even those workers might continue to be exempt if the municipalities in which they work opt out.

The city and county are jumping through these anti-business hoops at the behest of unions, which want the minimum public standards in place to give them better negotiating leverage with employers. But it’s not the job of public officials to help unions win better contracts. The unions can do that just fine on their own.

And, giving lawyers even more causes of action to pursue than they already have — all in the purported name of ensuring compliance — is foolhardy in the extreme. That is, if public officials care at all about the business climate in their jurisdictions and the ability of their businesses to remain competitive.

Cook County Commissioner Scott Britton, who co-sponsored Preckwinkle’s amendment to exempt parks and schools, explained the reason. “It is our responsibility as a board to guarantee workers’ needs are adequately met while balancing unintended consequences.”

In other words, “unanticipated consequences” in the public sector demand prompt action in Cook County and Chicago.

Not so in the private sector. It beggars belief.

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