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personal items, are borne by the lesser-time parent, who would otherwise not have provided these things

for a child rarely in his or her home. Yet the primary effect of the formula adjustment is to increase the

child support amount owed by the lesser-time parent, the very parent with arguably the greatest increase

in child-rearing costs.

There is, however, a mathematical reason for using such a multiplier. Use of a multiplier

artificially increases (only for purposes of the mathematical calculation) the “basic” child support that

would hypothetically be owed at the zero time-share level, which has the effect of reducing, though not

eliminating, the cliff effect. As is true of the simple below-threshold offset formula, as the income of the

primary parent becomes larger relative to the lesser-time parent, the size of the cliff effect increases. This

can be clearly seen in Appendices B2 and B4, which show steep drops in child support owed by a lesser-

time parent from Florida with more than 40 percent time-share, even though Florida is a state using a

“1.5” multiplier.

Complex “below-threshold offset” formulas can be used with any level of time-share threshold.

# Thresholds in states using this formula range from a low threshold of 20 percent time (Louisiana) to a

high of 40 percent time (Florida and the District of Columbia). In each of these states the shared time

formula is the same. The defining characteristic of the offset formulas used in these states is that the

threshold is not an element of the formula. The basic child support amounts (derived from a Melson

formula, an income shares model, or a percentage-of-income guideline) may differ somewhat, and the

thresholds may differ. But in all cases, the point at which the mathematical reduction calculation begins is

zero time, and the child support reduction formula is the same for all states using the “1.5” multiplier.

# Different threshold levels also have an effect on the size of cliff effects. Figure 5 shows the

results of the child support guidelines in three below-threshold offset states with a 1.5 multiplier, but with

different threshold levels (and also different basic child support levels). This figure demonstrates quite

clearly that in states with exactly the same formula, the lower the time-share threshold level, the lower the

cliff effect. Louisiana has the lowest basic child support level, the lowest threshold level, and also the

smallest cliff effect. Wisconsin, while having a higher basic child support level, has a lower threshold