'I am proud to work at ACME Corp.'
Our Murmur engagement survey includes an engagement index that is comprised of five questions  - this is one of them. This question is sometimes referred to as the 'pride' question (for fairly obvious reasons) but it is also called the 'heart' question (as in 'hearts, minds and hands' models), the 'emotive' question (as in 'rational, emotive, behavioural' models) or the BBQ or pub test question (not sure on the model here - maybe the sunday afternoon model).
A colleague once told me about a company he worked with who quintessentially passed the test - employees in this company were known to wear their boldly labelled work uniforms (aprons actually) down to the pub on Friday evening, for the entire evening. Put it this way - imagine being a BP employee attending a BBQ in late 2010 (just after the deepwater horizon oil spill) and someone asking you 'hey, where do you work?'.
For some organisations this feeling of pride is a tremendous asset, in particular this can drive employee resilience in organisations experiencing internal difficulties. In Not-For-Profit organisations it is often related to employees being connected with the mission and purpose of the organisation; in retail and hospitality it is often linked to brand image and it can be fostered by creating a sense of fun and excitement in the workplace. Strong pride can be found in old companies with great heritages and sometimes in emerging organisations with barely a year to their name.
The great thing about this question is that it is nearly aways indicative of GREAT places to work - but rarely for the same reasons.
 Nearly every management consultancy company have their own Engagement Index. An Engagement Index is a group of questions that are put together statistically (usually nothing more than an average) to provide a single number output that is then used to quantify Engagement. Some firms use hidden proprietary methods so that you cannot change survey vendors and maintain historical benchmarks - but that's a story for another day. A set of questions generally provides a better measure of something than a single question will for a variety of reasons. Those reasons are also the reasons why the exact set of questions are not as important as many people will try to tell/sell you. If you think about the index as a team of questions it just means that any individual question is not as important as the team.