Doesn't take an economics major to figure this out. when I first started SK, about a month after the launch, the ce price was at a steady 4k cr. Now it's about double the price. It's because of the high demand of ce. I am going to point out some crown sinks built in the game, but really the best way to combat the increase in price is to lower the payouts at runs. There are so many crowns in circulation right now, that OOO implemented some crown sinks like featured auctions, and it's really lowering the base value of the crown. CE price was low because crowns had more value. Decrease the payout during runs and you'll see a decrease in CE price.

Trade call and Investment advice? Let me stockpile up 100 x 100 energy, wait for demand to get high by not selling any CE, and sell them at 9kcr per piece. Apparently this has been happening. I notice some investors stockpiling up to 2000 x 100 energy during promotion periods, such as the Winterfest event, and the Black kat Kataclysmic event at 6kcr per piece, then selling them now at 7kcr per piece. Monopolization?

Inflation only seems to occur when demand is rising and supply is diminishing. Demand rises when people want to spend CE, such as crafting Kat Cowls. Supply rises to the extent that it has overtaken demand, therefore a drop in prices. When the event ends, the supply starts to diminish and prices start to rise due to the apparent fact that demand will not decrease rapidly as CE is still essential in gameplay.

1)Increase supply by injecting more CE into the market

This is the only viable option only when there are promotions, such as the 20% energy surplus available during a period of time during the Winterfest event. It is however noted that OOO does not interfere with the energy market directly. By promoting featured items, such as Moorcraft boxes, Winterfest boxes, OOO has successfully increased the supply of CE by increasing the number of buyers.

2)Decrease demand of CE (Imposing purchasing tax on the buyers)

This is impractical, due to the importance of CE in gameplay. By imposing taxes, you are slightly limiting the gameplay as one would have to pay more for the CE. However, it is unknown how this will decrease the demand for CE, as some people are still willing to pay the price.

3)Decrease the amount of supply of CR (Contractionary monetary policy)

By increasing the value of the virtual currency, energy prices may decrease, however at the extent that it is only a physical decrease in amount. Value of energy will still be treated as the same, and the price tag for 100 CE will adjust itself to suit the value of CR. By also decreasing the supply of CR, the whole economic system, that of trades, auction houses, vendors, will have to adjust itself. It is therefore, impractical.

4)Subsidy of CE for new players/buyers

OOO has in no direct way, interfere with the free market system the energy market seems to adopt. The only law for the free market is the 2% tax on every 100 CE sold, for anti-exploit reasons. Subsidies for CE can interfere the energy market. By giving a "discount", there is a flaw in which one questions the source of the money. Impractical as the two above.

TL;DR The nature of the energy market does not provide opportunities for OOO to help the poorer and newer knights in the SK community, however, OOO has been thoughtful and provided means to supply more CE to the market. In the end, only #1 is the solution, which has been implemented.

I see that you're studying for economics exam (I can smell a monetarist here).

While I like your analysis of the situation I believe that you forgot about the FSC grinding and elevators passes system which can be blamed for inflation. Since the economy in SK is more or less like laissez-faire type and the rules of suppy-demand work as well its impossible for inflation to increase endlessly. Therefore the market balances itself naturally (however this may take some time and discourage some new/f2p players from playing) and that's why it shouldn't be ignored and forgotten.

The 4 ideas of yours may cause disinflation but on the other hand some players may find them unfair (imagine those masses protesting in front of the AH). In fact the best (and the most efficient) way is to create appropriate crown sinks, like the whole GH update (we aren't Ikea, not yet), featured auctions on the AH, ce promos, kat event (wtf everyone's doing Arcade?). As far as I can see OOO has implemented such solutions succesfully.

Taxes aren't the way, it's the game economy in general what should be balanced (both ce and cr sinks) and the game itself (fun fun fun!) to attract more players. (easy I am not going to become a politician).

@Zephy: Wouldn't it just kill our dearest arcade which is already in agony? And wait, OOO has reduced the payout at least once (where's my 13k from FSC?!?!). It's not a big deal to wonder what would happen if ... or what should be done to... but first we must set our objectives (its it the cheap ce? (how cheap?) or the overall market balance or a steady rate of inflation? (what rate?))

In my opinion (and it's not only mine) the inflation rate should be reduced to the neutral amount (in which it doesn't affect our gameplay/decisions/good mood). Although the rate of exchange (cr/ce) may seem to be floating, OOO happens to take steps to reduce it (ce for 9k? Yes I remember that!).

Or you could just buy CE with real money and use it and never sell it. That works too.
Well... In result, the game would be 100% p2p (wow you see those masses fighting in front of the AH?) and a substantial part of our beloved community would vanish. (including me - (and you? ) - cryingface).

^ is biggest problem here. Making the currency vital to progression through the game buyable only through real money. Just imagine what would happen if nobody bought CE, nobody would go past lvl 2 items... but since people buying it, it leaves f2p in a complete disadvantage, as said above, and CE owners monopolists who dictate price for this vital to gameplay currency. I do not agree with this model what-so-ever. Just look at the other f2p games with non-vital-to-progression-real-money-bought currency, you can get same items, weapons, etc just by earning in-game cash by spending a bit more time, but you get them at a stable price unlike here, where prices depend on paying players. Developers can still earn (alot of)money from micro transactions, boosters, exclusive items, but leave the core gameplay pay2dominate free. Btf, the parallels with current U.S. monetary policy is spot on, but unlike in real world where paper money can be printed almost infinitely while physical goods have a limit, infinite amount of in-game currency can be supported by infinite amount of "special" currency if it could be bought as directly with in-game money(at a fixed price) as also with real money. That is the most just f2p model, and many games use this model while generating huge profits.
I haven't played this game for a year now, just wanted to check on things here but it seem nothing changed... If you really feel that this model suits you then it's fine, but for me (and probably many else) well, you already know how I feel about this... does anyone here care? I don't think so, I just wanted to express everything I thought about the subject, since it surfaced(again).

@Zaffy-Laffy Number 3 has been implemented in the form of guild hall updates. This was a massive crown sink and took a good chunk of the supply of CR out of the player base. (also note that the 10 dollar guardian armor pack promo was introduced at the same time, which magnified the cr price reduction even more)