Israeli Polls Show Wide Discrepancies Due to Sampling and Method Differences
As millions of Israelis prepare to vote in the upcoming Knesset elections, polls continue to present conflicting pictures of the political landscape. Despite surveying only several hundred to about 1,000 individuals, polling institutes attempt to represent the entire voting population through different sampling methods and data collection techniques. This results in significant variations, with some polls showing the Likud party at 21-24 seats while others place it between 27-35 seats, creating gaps of up to 10 mandates.
Experts highlight that the core issue lies in how each polling institute constructs its sample. Dr. Menachem Lazar, head of Lazar Research Institute, explains that samples must reflect the population's demographic proportions, including gender, age, region, and religious affiliation, which heavily influences voting behavior. However, the methods of data collection, telephone surveys, internet panels, or mixed approaches, each miss different segments of the population, such as the elderly, the Haredi community, or Arab Israelis, who may have lower internet access or be less likely to respond.
Polling firms try to compensate for these gaps through statistical weighting and mixed sampling methods. For example, Meno Geva of the Midgam Institute, which conducts polls for Channel 12, emphasizes combining telephone and internet surveys to reach diverse groups effectively. Dr. Lazar relies mainly on internet panels but supplements with telephone surveys for underrepresented groups. Despite these efforts, some populations remain underrepresented, leading to inherent uncertainties.
Differences in how pollsters weigh groups, handle undecided voters (about 15% in most polls), and adjust for turnout expectations contribute to the wide disparities seen between polls. Dr. Lazar notes that while small differences in Likud's seat count are acceptable, gaps of 10 to 15 seats indicate fundamentally different sampling bases. Additional factors such as question wording, timing relative to political events, and the media outlet's audience may also influence results.
Ultimately, while polls provide snapshots of voter intentions, their methodological variations mean no single poll can definitively predict election outcomes. Voters and analysts should interpret poll results cautiously, understanding the complexities behind the numbers.
