MAD DUCK: With midnight regulation, Obama Energy Department just outlawed your three-way bulb.

Three-way bulbs, which have two different filaments and thus three different brightnesses, are currently exempted. DOE just ruled that they now need to be covered. The Department’s reasoning: “DOE expects these sales will likely increase since these lamps could be used as replacements for other regulated lamp types.” In other words: People might start buying these bulbs because they want regular light bulbs rather than expensive LEDs or crappy fluorescents.

DOE also spiked the exemption for globe-shaped bulbs. Many manufacturers make, and many retailers sell, globe-shaped bulbs that met the standards, but consumers were left with the option to buy globe-shaped bulbs of the old type. That couldn’t stand.

This rule doesn’t go into effect for three years, but it could lead pretty quickly to domestic bulb makers ceasing production.

It’s Friday.