Previous empirical studies of multiple job holding have tended to focus on the characteristics of those obtaining off-fann employment and the factors affecting the hours supplied to those obtaining off-farm activities. None of these studies have explicitly addressed the reasons behind the decision to seek off-farm employment. Neither have they been able to examine in-depth the important issue of how this major component of the farm sector responds to alternative policies, since most studies have used cross-sectional data for a given region. A comparison between countries would permit the analysis of how multiple job holding responds to differing government policies. The purpose of this paper is to examine the reasons for and factors affecting multiple job holdings of dairy farm families in neighboring regions of two counties, United States and Canada. The bordering regions of New York and Ontario have similar geographic conditions but significantly different farm support and social service policies. The results indicate the importance of farm income on why people work off the farm and provide evidence of multiple job holding as a flexible mechanism for coping with changes in the economic environment facing the household. For operators, the driving characteristics influencing off-farm labor participation is the farm's financial position. The supply-managed milk marketing system ensures higher and more stable returns for Ontario dairy farm labor. In contrast, it is family demographics, educational level and social support policy that appears to largely influence spousal off-farm employment decisions. Free medical care in Ontario lowers the reservation wage for household members. The effect of these farm and social support policies on the relative returns to labor in agriculture and non-farm employment explains the lower participation rate and hours supplied in off-farm work by both operators, and hours supplied in off-farm work by both operators and spouses in Ontario dairy farm household. Published by Elsevier Science B.V.