Solution:(1) The imposition of a tax on a commodity changes its price. If the price changes, the income effect and the substitution effect will occur.
(2) A lump-sum tax does not affect marginal cost in the short run, so the price will not change. Therefore, the substitution effect and the income effect do not occur.
(3) The greater the substitution effect, the greater the burden loss.
(4) The burden loss is associated with the reduction in prices received by producers as a result of the imposition of the tax.