This article examines real estate platforms and the data they generate to provide new insights into housing markets and practices, focusing on lower-cost and informal sectors, where building or rental regulations are often bypassed or contravened. We examine online listings advertised in Sydney, one of the most expensive cities in Australia and the world, compiling data from four dominant platforms – Realestate.com.au, Flatmates.com.au, Gumtree.com.au and Airbnb.com – each of which offers a particular type of rental accommodation. Using these datasets, we identify a typology of lower-cost and informal tenures and dwelling units, ranging from secondary dwellings and illegally subdivided apartments to shared accommodation and precarious rental agreements. Our study highlights a supplementary supply of rental housing, operating within the conventional private rental market, accessed and made visible via the platforms we examine. Applying a statistical regression approach, we examine relationships between concentrations of informal housing supply and socio-economic variables. The findings reveal intersections between digital platforms and evolving informal market practices and have implications for urban planning and housing policy.

中文翻译：

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补充租赁供应？澳大利亚悉尼低成本和非正式住房的数字市场


本文研究了房地产平台及其生成的数据，以提供对住房市场和实践的新见解，重点关注低成本和非正规部门，这些部门的建筑或租赁法规经常被绕过或违反。我们检查了悉尼（澳大利亚和世界上最昂贵的城市之一）广告中的在线列表，并从四个主要平台（Realestate.com.au、Flatmates.com.au、Gumtree.com.au 和 Airbnb.com）收集数据。其中提供特定类型的出租住宿。利用这些数据集，我们确定了低成本和非正式的保有权和住宅单元的类型，范围从二级住宅和非法细分公寓到合租住宿和不稳定的租赁协议。我们的研究强调了租赁住房的补充供应，在传统的私人租赁市场内运营，通过我们研究的平台访问和公开。应用统计回归方法，我们研究了非正规住房供应集中度与社会经济变量之间的关系。研究结果揭示了数字平台与不断发展的非正式市场实践之间的交叉点，并对城市规划和住房政策产生影响。