Zero-sum thinking

Definition 

From Wikipedia: "Zero-sum thinking, also known as zero-sum bias, is a cognitive bias that describes when an individual thinks that a situation is like a zero-sum game, where one person's gain would be another's loss.The term is derived from game theory. However, unlike the game theory concept, zero-sum thinking refers to a psychological construct—a person's subjective interpretation of a situation. Zero-sum thinking is captured by the saying "your gain is my loss" (or conversely, "your loss is my gain"). Rozycka-Tran et al. (2015) defined zero-sum thinking as:

"A general belief system about the antagonistic nature of social relations, shared by people in a society or culture and based on the implicit assumption that a finite amount of goods exists in the world, in which one person’s winning makes others the losers, and vice versa [...] a relatively permanent and general conviction that social relations are like a zero-sum game. People who share this conviction believe that success, especially economic success, is possible only at the expense of other people’s failures." (pps. 526–528).^[2]

In land-use

"I think many old-school SF housing advocates do have a kind of zero-sum viewpoint about development, and this is helpful for understanding them. Here's #CalvinWelch stating it explicitly:"  - @YIMBYwiki on Twitter, 26 Dec 2017. 

"San Francisco’s housing movement stems from its severely constrained development potential: it has limited land capacity, roughly 47 square miles on the tip of a peninsula, with no ability to expand through Bay infill or annexation; and it is 'built out,' with almost all its available land developed. Consequently, 'development in the City is a zero sum game, with winners and losers. With minor exceptions, new development in San Francisco, residential or commercial, means the demolition and displacement of what was there.'[1]"
     [1]: Interview with Calvin Welch, San Francisco housing activist, lecturer in development politics, and former longtime Co-Director of the Council of Community Housing Organizations, July 20, 2012.

above quote is from Rosen [2012]. 

Response from Laura Foote Clark, Executive Director of YIMBY Action, @NeverSassyLaura on Twitter 26 Dec 2017.

"IMO best strategy for overcoming those with a zero-sum mentality is offer to help them achieve their positive goals. Either they reject your help (proving their own partisanship or hypocrisy) or they accept and you can begin to build genuine connections to achieve common goals."
 

^References

• Rosen, Marcia, and Wendy Sullivan. “From Urban Renewal and Displacement to Economic Inclusion: San Francisco Affordable Housing Policy 1978-2012.” Poverty and Race Research Action Council, November 2012. 
  http://www.prrac.org/pdf/SanFranAffHsing.pdf. 
   
• Rozycka-Tran, J.; Boski, P.; Wojciszke, B. (2015-03-19). "Belief in a Zero-Sum Game as a Social Axiom: A 37-Nation Study". Journal of Cross-Cultural Psychology. 46 (4): 525–548. doi:10.1177/0022022115572226.