When San Francisco and other cities in California adopted soda taxes, an opinion column in the New York Times observed, “Often, the taxes don’t even pinch the budgets of low-income families, because they respond by drinking less soda.” What does the columnist mean when he writes that soda taxes don’t “pinch the budgets” of low-income families? Shouldn’t an increase in the price of soda resulting from a tax always increase the amount that families have to spend to buy soda? Briefly explain.