3) Consider the following panel data regression with a single explanatory variable Ya = 13) + 181Xi: + qu' In each of the examples below, you will be adding entity and time fixed effects. Indicate the total number of coefficients that need to be estimated. (a) The effect of beer taxes on the fatality rate, annual data, 1982-1988, nine U.S. regions (New England, Pacific, Mid-Atlantic, East North Central, etc.). (b) The effect of the minimum wage on teenage employment, annual data, 1963-2000, five Canadian Regions (Atlantic Provinces, Quebec, Ontario, Prairies, British Columbia). (c) The effect of savings rates on per capita income, data for three decades (1960-1969, 1970