RENT CONTROL SURVEY: IS IT VALID?

Los Angeles recently spent $600,000 on a landmark survey designed to find out how its rent control law was working, so that lawmakers could see whether landlords or tenants were being treated unfairly and make changes in the law to remedy any harms.

Pollsters for the city telephoned 2,299 tenants in the city and 404 others who lived outside the city and had no rent control. They got information from 82% of the tenants called.

Pollsters also contacted landlords. They mailed questionnaires to 2,550 landlords--2,494 in the city and 56 outside. But 86% of landlords surveyed did not respond.

The small landlord sample has raised questions about whether the survey provided valid information about how landlords are faring.

To answer these questions, The Times turned to two experts in the field of public opinion polling--Leslie Kish, retired head of the sampling section of the University of Michigan’s Institute for Social Research, and Jay Schmiedeskamp, a senior vice president of the Princeton, N.J.-based Gallup Organization.

Addressing the same questions was Francine Rabinovitz of the consulting firm that managed the survey for the city.

Question: Was the landlord sample adequate to support the survey’s conclusion that, in general, city landlords were neither hurt nor helped by rent control?

Schmiedeskamp: “I would really not place very much faith in the survey’s findings . . . When you have a response rate that low, you have a very large potential for . . . bias (being introduced into the survey, for example, by landlords whose profits may have been high and who may have chosen not to respond because they feared their responses might lead to a tougher rent control law.) Were those who filled out the questionnaire a lot different from those who did? The point is you just don’t know.”

Kish: “There’s no strict line when (a sample) ceases to become a valid sample. . . . (But) no, (the landlord sample) is not completely reliable . . . They should have gone back and tried to get the non-responders. . . . I would have used more mailings. . . . You cannot justify not going after more...”

Rabinovitz: “We did try to reach each landlord in the sample at least four times and some in person. . . . We would prefer to have had a much more robust response . . . and to know more about the characteristics of the non-respondents. . . . We do not know what the non-respondents are like. But the survey is not worthless.”

Question: Because survey takers wanted income and expense data from sources other than landlords, they sought corroborative information from the California Franchise Tax Board; the Institute of Real Estate Management in Chicago, a national association of landlords and commercial property owners; and Damar, a Los Angeles-based firm that collects data on private property sales and appraisals.

Did information from these other sources bolster the small landlord sample sufficiently to make the survey valid?

Schmiedeskamp: “You can use (the other data) to validate certain things but not everything. . . . A survey with a return that low doesn’t mean that much. You may or may not have a representative sample (to compare with the other data). . . . I wouldn’t put my name on it. . . . If you have good data from other sources then why did you do the survey to begin with?”

Kish: “I was impressed with the (effort to get other data). (Nevertheless) I would accept the (landlord) data with some caution. . . . The other data may be good but the survey (on balance) is still subject to serious questions.”

Rabinovitz: “The survey is useful because the results (from the landlords) track very well with the results from three other data sources.”