$1.$ Give an extended definition of a frontline worker, and provide at least $3$ estimates of the percentage of the workforce that can be considered frontline workers. Cite your sources. Your reference list cannot include blogs, digital magazines, personal opinions, popular press articles, or popular press books. Your reference list must consist entirely of information from academic textbooks, academic journals, highly reputable practitioner journals $($e$.$g$.,$ Harvard Business Review, Sloan Management Review$),$ government studies or databases, national polling data, etc. $(1/2$ point$)$