The “above threshold offset” formula can be expressed in a wide variety of ways. Using the
Wisconsin shared placement threshold of “25 percent of time or more”, we have prepared three methods
of expressing this calculation. (The Wisconsin time-share threshold is stated as “25 percent of time or
more,” and as such, is technically a 24 percent threshold, since reductions in child support amount take
place after that level.)
One method of expressing this formula is presented in Addendum Ia, using the Wisconsin
threshold level expressed as a percentage of time. A second method expresses the formula in terms of the
number of days that each parent cares for the child. This method is presented with a number of examples
in Addendum Ib. A third method also expresses the formula in terms of the percentage of time, but
replaces some of the computation by referring to a table of multipliers. This method is presented, with a
number of examples, in Addendum Ic and with a table of multipliers in Addendum Id.
In Figures 7.1–7.6 we compare three child support formulas, using the same income scenarios as
Appendices B1 through B6. These three formulas are: a) the current Wisconsin shared placement
guidelines, instituted in 2004, b) the guidelines that were in place in Wisconsin from 1995 through
2003,26 and c) the “Proposed” formula. It should be noted that the current guideline and the proposed
guideline are based on Wisconsin’s current time-share threshold of “25 percent of time or more”, whereas
the former guideline of 1995–2003 used a “more than 30 percent” time-share threshold.
26 The 1995–2003 Wisconsin shared placement guideline was a two-part formulation, which can be described as a complex graduated formula, with a percent-by-percent graduated reduction of the lesser-time parent’s child support order from 31 to 40 percent time-share, and an above threshold offset formula beginning at 41 percent time-share. As such, this guideline precluded a lesser-time parent from being a child support payee at time-share levels below 41 percent—an effect of the graduated part of the guideline. By switching to an offset formula at 41 percent time-share, the greater-time parent could have been named as the child support payee at that level of time- share or higher, if there had been a large imbalance between parent incomes.