What Income is Looked at when Determining Child Support

[teeter979]

State: Texas
My boyfriend recently received a notice from the Attorney General that he is eligible to review his current child support order for his 2 children.
When the original order was made it was based on his ex-wife's claim that he made $50,000 a year and he was ordered to pay approx. $200/wk. He is in a union and makes enough to pay that amount when he is working, but due to the poor economy he has long periods of unemployment, the last one lasting 8 months. When he is receiving unemployment, half of his benefits go to childsupport leaving his income at only $200/wk. He recently returned to work, but that job is only expected to last through April.
My question is: What period of time is considered when he files for this review? Is it his current earnings, the total earnings over the last year, or some other time period?
It seems unfair to base the amount on his work earnings when he is currently working for less than half of the year and we can barely support ourselves when he is waiting for a new project to begin.

[Dogmatique]

Is he able to take on other work while he's not able to do his regular job?

It's likely that he'll be imputed at least mininum wage during the periods he's unemployed.

[teeter979]

With the amount of CS he owes, he can't afford to take a lower paying job because we would be left with nothing to live on. Don't get me wrong, he would much rather work than collect unemployment. Unfortunately, his unemployment pays much more than what he has found out there and keeps him from falling behind in his payments.
Do you know how to calculate the estimated CS payments? I have tried to use the calculators online, but I don't know what to put as his income. The average monthly income from last years earnings or the actual amount he is earning per month right now?

[Dogmatique]

They'll take the average monthly income during the year prior to the date of filing, as a rule - but be aware that in his situation, they could very well use his past earnings to calculate the support.

(in other words, they CAN calculate the amount based upon his potential earnings)