Section 183 is applicable here and the Regulations thereunder are instructive (i.e. activity or business):
Section 1.183-1(d)(1):
Ascertainment of activity. In order to determine whether, and to what extent, section 183 and the regulations thereunder apply, the activity or activities of the taxpayer must be ascertained. For instance, where the taxpayer is engaged in several undertakings, each of these may be a separate activity, or several undertakings may constitute one activity. In ascertaining the activity or activities of the taxpayer, all the facts and circumstances of the case must be taken into account. Generally, the most significant facts and circumstances in making this determination are the degree of organizational and economic interrelationship of various undertakings, the business purpose which is (or might be) served by carrying on the various undertakings separately or together in a trade or business or in an investment setting, and the similarity of various undertakings. Generally, the Commissioner will accept the characterization by the taxpayer of several undertakings either as a single activity or as separate activities. The taxpayer's characterization will not be accepted, however, when it appears that his characterization is artificial and cannot be reasonably supported under the facts and circumstances of the case. If the taxpayer engages in two or more separate activities, deductions and income from each separate activity are not aggregated either in determining whether a particular activity is engaged in for profit or in applying section 183. Where land is purchased or held primarily with the intent to profit from increase in its value, and the taxpayer also engages in farming on such land, the farming and the holding of the land will ordinarily be considered a single activity only if the farming activity reduces the net cost of carrying the land for its appreciation in value. Thus, the farming and holding of the land will be considered a single activity only if the income derived from farming exceeds the deductions attributable to the farming activity which are not directly attributable to the holding of the land (that is, deductions other than those directly attributable to the holding of the land such as interest on a mortgage secured by the land, annual property taxes attributable to the land and improvements, and depreciation of improvements to the land).
