Originally posted by TwoUptons If you quarter the market, you have to double the price.
I haven't been annoyingly pedantic for a while, so here goes. The inverse relationship you are referring to involves gross margin, not net price and is assuming that fixed costs are constant. In that case, your equation is true if gross margin was 50%, then doubling the price when sales volume decreases by 75% will result in the same gross profit. Fortunately, for price sensitive consumers at least, fixed costs seldom stay the same if sales volume decreases by 75%, so a relatively small increase in price can make up the difference in most cases. The other consideration is that most manufacturers cannot turn the tap on or off at will, so the primary concern is to cover ongoing costs in order to keep the lights on, as opposed to shutting down as soon as net profit declines.
None of which has a real bearing on whether or not a particular camera manufacturer will keep producing cameras in a declining market. The people who own the manufacturer (or more realistically their proxies, whether they are other corporations or investment funds or executives who are incentivized by stock options) determine what is required to keep producing cameras. No corporation simply stops operating a line of business because it fails to meet a performance threshold; someone somewhere is held responsible for mitigating the losses involved and an escape hatch will be opened; if necessary an imaginary escape hatch will be created. Assets of debatable value are sold or traded for other assets of debatable value, accounting "adjustments" are made after a change of the guard and so on.
If I could ever get the timing of my predictions right, I would be much wealthier than I really am. The same song gets played over and over again, just in a different key and with a different tempo.