http://www.divorcenet.com/pa/chap3.html#6
http://www.pennsylvanialawonline.com/pa/family/pacldsupguidelines.htm
RULE 1910.16-5. Support Guidelines. Operation.
(c) Reduced or Fluctuating Income.
1. Voluntary Reduction of Income. Where a party voluntarily assumes a lower paying job, there generally will be no recomputation of the support payment. A party ordinarily will not be relieved of a support obligation by voluntarily quitting work or by being fired for misconduct.
2. Involuntary Reduction of Income. No adjustments in support payments will be made for normal fluctuations in earnings. However, appropriate adjustments will be made for substantial continuing involuntary decreases in income.
3. Seasonal Employees. Support orders for seasonal employees, such as construction workers, shall ordinarily be based upon a yearly average.
4. Bonuses. Bonuses which are received in addition to periodic compensation may be annualized and included in the party's net monthly income. The treatment accorded bonuses should be considered carefully, particularly in times of economic difficulty.
<b>5. Income Potential. Ordinarily, a party who willfully fails to obtain appropriate employment will be considered to have an income equal to the party's earning capacity. Age, education, training, health, work experience, earnings history and child care responsibilities are factors which shall be considered in determining earning capacity. </b>