previous year. Furthermore, his business might be considered a hobby by the IRS. That would disallow any loss.

Consider the following:
"The IRS has a list of nine factors to be used in determining whether an activity is a legitimate business or a hobby:

Whether you carry on the activity in a businesslike manner and maintain complete and accurate books and records.
Whether the time and effort you put into the activity indicate you intend to make it profitable.
Whether you depend on income from the activity for your livelihood.
Whether your losses are due to circumstances beyond your control (or are normal in the startup phase of your type of business).
Whether you change your methods of operation in an attempt to improve profitability.
Whether you or your advisors have the knowledge needed to carry on the activity as a successful business.
Whether you were successful in making a profit in similar activities in the past.
Whether the activity makes a profit in some years and how much profit it makes.
Whether you can expect to make a future profit from the appreciation of the assets used in the activity."