The Canadian Shift is a chain shift of vowel sounds found in Canadian English, beginning among speakers in the last quarter of the 20th century and most significantly involving the lowering and backing of the front vowels. This lowering and backing is structurally identical to the California Shift reported in California English and some younger varieties of Western New England English, Western American English, Pacific Northwest English, and Midland American English; whether the similarly structured shifts in these regional dialects have a single unified cause or not is still not entirely clear. The back and downward movement of all the front vowels was first noted in some California speakers in 1987, then in some Canadian speakers in 1995 (initially reported as two separate phenomena), and later documented among some speakers in Western and Midland U.S. cities born after 1980, based on impressionistic analysis. Assuming the similar chain shifts found in Canada and various parts of the U.S. are a phenomenon with a single common origin, a variety of names have been proposed for this trans-regional chain shift, including the Third Dialect Shift, Elsewhere Shift, Low Back Merger Shift, and Short Front Vowel Shift. Canadian Shift in Canada The shift involves the lowering of the tongue in the front lax vowels (the short-a of trap), (the short-e of dress), and (the short-i of kit). It is triggered by the cot–caught merger: (as in cot) and (as in caught) merge as , a low back rounded vowel. As each space opens up, the next vowel along moves into it. Thus, the short a retracts from a near-low front position to a low central position, with a quality similar to the vowel heard in Northern England . The retraction of was independently observed in Vancouver and is more advanced for Ontarians and women than for people from the Prairies or Atlantic Canada and men. However, scholars disagree on the behaviour of and : According to Clarke et al. (1995), who impressionistically studied the speech of a few young Ontarians, and tend to lower in the direction of and , respectively. Hence, bet and bit tend to sound, respectively, like bat and bet as pronounced by a speaker without the shift. Labov et al. (2006), through acoustic analysis of 33 subjects from all over the country, noted a backward and downward movement of in apparent time in all of Canada except the Atlantic Provinces.