David Shipley, et al., Appellants, vs. Duane Sjoblom, d/b/a Sjoblom's Nursery, Respondent.

may not be cited except as provided by

Minn. Stat. § 480 A. 08, subd. 3 (1996).

 STATE OF MINNESOTA

 IN COURT OF APPEALS

 C6-97-1792

State of Minnesota, et al.,

Respondents,

vs.

Timothy William Glowczewski,

Appellant.

 Filed April 7, 1998

 Affirmed

 Short, Judge

Winona County District Court

File No. F89050104

Charles E. MacLean, Winona County Attorney, Nancy L. Buytendorp, Assistant County Attorney, Winona County Courthouse, 171 West Third Street, Winona, MN 55987 (for respondents)

John Paul Plachecki, 59 West Third Street, P.O. Box 617, Winona, MN 55987 (for appellant)

Considered and decided by Harten, Presiding Judge, Short, Judge, and Amundson, Judge.

 U N P U B L I S H E D O P I N I O N

 SHORT, Judge

On appeal from an order modifying his child support amount pursuant to Minn. Stat. § 518.64, subd. 2 (1996), Timothy William Glowczewski argues the evidence and findings fail to support the administrative law judge's decision to impute income, and in the alternative, the ALJ's calculation of income. We affirm.

  D E C I S I O N

Subject to certain limitations, an administrative law judge (ALJ) has the same power as a trial court in modifying child support obligations. Minn. Stat. § 518.5511 subd. 1(e) (1996). An ALJ is afforded broad discretion in child support cases, and we must affirm its decision absent a clear abuse of that discretion. See Minn. Stat. § 518.5511, subd. 4(h) (1996) (providing decisions of ALJ are appealable in same manner as decisions of trial court); Lee v. Lee, 459 N.W.2d 365, 368-69 (Minn. App. 1990) (concluding trial court standards of review are applicable to review of ALJ's order in child support modification cases), review denied (Minn. Oct. 18, 1990). Under an abuse of discretion standard, we ask "whether the trial court abused its discretion by making findings unsupported by the evidence or by improperly applying the law." Ayers v. Ayers, 508 N.W.2d 515, 518 (Minn. 1993) (citations omitted).

I.

Generally, "the obligation to pay child support is premised on the obligor's ability to pay." Schneider v. Schneider, 473 N.W.2d 329, 332 (Minn. App. 1991). However, a court may impute income for the purpose of calculating child support if the obligor is voluntarily unemployed or underemployed. Minn. Stat. § 518.551, subd. 5b(d) (1996); Franzen v. Borders, 521 N.W.2d 626, 629 (Minn. App. 1994). A trial court is precluded from imputing income when the obligor's unemployment or underemployment: (1) is temporary and will ultimately lead to an increase in income; or (2) represents a bona fide career change, which outweighs the adverse effect of the obligor's diminished income on the child. Minn. Stat. § 518.551, subd. 5b(d); Franzen, 521 N.W.2d at 628-29. The burden is on the obligor to demonstrate the existence of one of these statutory factors. Minn. Stat. § 518.551, subd. 5b(d).

It is undisputed that the "change of circumstances" threshhold for modification has been met by Glowczewski's substantial increase in income. Glowczewski argues the evidence fails to support the ALJ's findings that he was voluntarily underemployed and the ALJ's decision to impute income of $7 per hour during the four months "off season." We disagree. The record demonstrates: (1) Glowczewski and his brother formed a partnership for the purposes of operating their parents' seasonal restaurant, and took over that restaurant's operations in 1993; (2) Glowczewski earns $1,362.82 per month during the eight months he works at the restaurant; (3) Glowczewski has a bachelor's degree in business; (4) prior to forming the partnership, Glowczewski worked various jobs, earning between $5 and $7 per hour; (5) there is no evidence Glowczewski is disabled or unable to work during the "off season" of his restaurant business; and (6) Glowczewski has chosen to remain at home during the "off season" with his children from his current marriage. Given these facts, the ALJ's finding that Glowczewski is underemployed is amply supported by the record. After a careful review of the record, we conclude the ALJ did not err in imputing income to Glowczewski. See Minn. Stat. § 518.551, subd. 5b(d) (defining "imputed income" as estimated earning ability of obligor, based on obligor's prior earning history, education, job skills, and availability of jobs within community for individual with obligor's qualifications); cf. Juelfs v. Juelfs, 359 N.W.2d 667, 670 (Minn. App. 1984) (affirming denial of child support obligation where obligor voluntarily changed employment, and presented only his speculation that the new business would prosper in future), review denied (Minn. Mar. 29, 1985); see, e.g., Devault v. Waller, 494 N.W.2d 92, 97 (Minn. App. 1992) (concluding one's choice to do valuable work for spouse, and to decline paycheck for the work, should not determine parent's support obligation to minor children).

In the alternative, Glowczewski argues the ALJ erroneously adjusted his income to reflect an overpayment of wages to his mother that was contrary to the partnership tax return. However, tax returns may be insufficient to determine income, and the trial court can consider "cash flow" in addition to "paper income." Coady v. Jurek, 366 N.W.2d 715, 718 (Minn. App. 1984), review denied (Minn. June 27, 1985); see also Otte v. Otte, 368 N.W.2d 293, 297 (Minn. App. 1985) (concluding tax returns alone may be insufficient to determine income of self-employed person); Ferguson v. Ferguson, 357 N.W.2d 104, 108 (Minn. App. 1984) (stating self-employed person may be self-supporting, yet report negligible income). It is undisputed: (1) Glowczewski's parents continue to own the land and restaurant building, and rent to their sons; (3) Glowczewski's mother works in the restaurant as a cook, earning $11.25 per hour, while a reasonable market wage for a short order cook is $7 per hour, resulting in a $2,210 difference between the market wage and her actual wage; and (3) the reported expenses of the partnership included the wages paid to Glowczewski's mother. Under these circumstances, the trial court's findings have a reasonable basis in fact and we cannot say the trial court erred in adjusting the actual business expenses to compensate for the overpayment of income to Glowczewski's mother. See Strauch v. Strauch, 401 N.W.2d 444, 448 (Minn. App. 1987) (concluding reviewing court will not reverse trial court's determination of net income used to calculate child support if it has reasonable basis in fact).

  Affirmed.