This raises two critical issues: (1) Why do Google and other firms do this? Google gets 130 applications for each opening, so its selection problem is how to find the best people using a cost effective process. With such a high applicant to hire ratio, Google has no problem attracting persons who meet job qualifications.
Google isn't looking for the smartest, or even the most technically capable, candidates. Google is looking for the candidates who will best fit Google.(2) What is the likely impact on labor markets and society? The hiring process involves selecting predictors that will inform the decision and be cost effective. Research has shown that traditional job interviews are not very good predictors of future performance and can result in bias (interviewers give high evals to people who are most like themselves). Increasingly, firms use a work-sampling approach to make decisions.
There is significant evidence that "work sampling," the use of tests similar to the work being performed, is a better predictor of future performance than the usual job-interview chit-chat. Google does a lot of work sampling, such as requiring coders to write code in the interview. The rationale for the creative-thinking questions is that they test the type of mental processes used in inventing a new product or developing a new business plan.I doubt Google has experimental evidence that asking job candidates questions like "Suppose you were shrunk to a height of a nickel and dropped into a blender ..." actually works. It is far from clear that giving a snap answer to such questions yields better decisions than an approach that allows for reflection and research (especially if the goal is creativity and innovation). But until the ratio of applicants to positions shrinks, the practice is unlikely to change. Suggestion to job seekers: websites such as glassdoor.com allow interviewees to post about their experiences; be sure to check it out before you get asked to design an evacuation plan for San Francisco.