A reconnaissance of housing-related industries (residential mortgage lending, real estate brokerage, home repair and remodeling, property insurance, home improvement financing) in Brown County, Wisconsin, Site I of the Housing Assistance Supply Experiment, suggests that: (1) Home purchases by participants in the experimental housing allowance program will be few, the final number depending on the posture of mortgage lenders and insurers. (2) Efforts to bring housing up to program standards should create a market for home repair and improvement contractors without straining the industry's capacity. (3) It is difficult to judge the probable effect of realtors' policies on marginal neighborhoods. (4) Management and maintenance firms, rental agents, and insurance companies are not pertinent to the experiment. Future research will include informal local inquiries and collection of data from public records, the Housing Allowance Office, formal surveys of landlords, homeowners, and mortgage institutions. Special attention will focus on two marginal areas of Brown County's housing market.