David,
A New Jersey Court's authority to impute income when fixing Child Support is incorporated in the New Jersey Child Support Guidelines (Guidelines).See R. 5:6A (adopting Guidelines set forth in Appendix IX-A to the Court Rules). Jump to In Miller v. Miller, 160 N.J. 408 (1999), where the Supreme Court of New Jersey was faced with the issue of whether income should be imputed from a supporting spouse's investments for the purpose of determining his or her ability to pay alimony pursuant to an agreement. Thus, the Supreme Court concluded that it was appropriate to impute a reasonable income from plaintiff's investments comparable to a prudent use of his investments, like his human capital. The question remained, however, regarding the rate of return that should be applied to plaintiff's investment decisions. The court concluded that the fairest solution for imputing income to plaintiff's investments under the present circumstances would be to impute a rate of return based on long-term corporate bonds and that the rate should be based upon Moody's Composite Index on A-rated Corporate Bonds. Id. at 425. Thus, the court averaged the long-term corporate bond rate of return over the preceding five (5) years and concluded with a 7.7% rate of return. Id. (Caveat: This rate has gone down since that time. As of 6/7/2016, the Moody's Bond Yield Average – A Rated Corporates (5-year average): 4.34%.) I'm sure it's changed since then.
However, you must also review Overbay v. Overbay, 376 N.J. Super 99 (App. Div. 2005). The Court was faced with the issue of a dependent spouse's need for alimony was considered in light of her receipt of various monetary gifts and inheritances she received during the marriage from family members, including her mother and her aunts that were valued at $1,143,695. The court again relied upon Aronson v. Aronson, 245 N.J.Super. 354, 363, (App.Div.1991) citing its holding that "although inheritance is exempt from equitable distribution, income generated by a dependent spouse's inheritance is no different from in-come generated by any other asset, exempt or otherwise, for an alimony analysis." The court in Overbay, imputed income to the wife based upon her investments but improperly (per Appellate Court) relied upon the Miller holding by using a 7.4% rate of return on inheritance assets. The Appellate Court held that the Miller holding was "fact sensitive", mostly based upon the fact that Mr. Miller was an experienced investor. Thus, applying the same rate of return was not proper in Overbay. The court held that the lesson learned from Miller is that when a spouse with under-earning investments has the ability to generate additional earnings--without risk of loss or depletion of principal--but fails to do so, it is fair for a court to impute a more reasonable rate of return to the under earning assets, comparable to a prudent use of investment capital. Id. at 111. While the Appellate Division remanded, it added that "the trial court must first decide whether it is appropriate to impute additional earnings from defendant's inheritance "comparable to a prudent use of [her] investments." Miller, supra, 160 N.J. at 424, 734 A.2d 752. If additional earnings are to be imputed, the court must then determine the reasonable amount of additional income to be attributed to defendant. See Caplan v. Caplan, 182 N.J. 250, 270 (2005) ("Once the trial court decides that income should be imputed, the next step is to determine the reasonable amount of income to be imputed to that party."). Id. at 112. The Overbay Appellate Court also held that if the trial court determines that defendant's investments provide a prudent balance between investment risk and investment return, then additional income should not be imputed even though a more aggressive investment strategy might provide additional earnings. A litigant is not required to put his or her capital at risk, or to jeopardize his or her inheritance, by pursuing an investment strategy that is neither reasonable nor prudent. Id. at 112-113.
Bottom line is that the Overbay court created a very fact-sensitive approach without the level of guidance provided by Miller.