Arnold Kling: Robin Hanson asks why parking should be free, when there are thousands of other goods with low marginal cost that are not free. My basic answer is that there are thousands of other goods with low marginal cost that are free. I think of free parking as a form of bundling, where the supplier of a priced good (a house, or a store) throws in another for free. If you think bundling is exceptional, then you must be shocked every time you buy a car with cup holders, a cell phone with a camera, or a computer that comes with a USB port, a WI-FI antenna, and word processing software. …