He feels duty-bound to participate materially in this political controversy rather than merely remaining in his studious retirement, however pleasant that is, at his father's house.

他觉得自己有责任积极参与到,这场政治争端中来,而不是仅仅拘泥于晚年的学究生活，不管那种生活是多么的惬意。

耶鲁公开课 - 弥尔顿课程节选

Using more correct terminology, the question is whether you materially participate in the condo rental business.

FORBES: Why 'Material Participation' Can Be Your Ticket To Tax Deductions

The IRS usually says you must spend a minimum of 500 hours working on each property to materially participate a very tough standard to meet.

FORBES: How Real Estate Investors Can Protect Themselves From The IRS

It may appear that ramping up your hours to materially participate in an activity is a no-brainer, because by converting the activity from passive to nonpassive, you can pull the resulting income out of the computation of net investment income and save an extra 3.8% in tax.

FORBES: Overview Of The New 3.8% Investment Income Tax, Part 2: Passive Activities