Image result for switzerlandThe engine of philatelic popularity and growth over the 170 or so years that philately has been a hobby has traditionally been the stamps of Central Europe-Germany and its numerous component areas, Switzerland, Austria and to a lesser extent Liechtenstein. In 1930 there were probably as many serious German collectors as there were in the rest of the world combined. The numbers are dwindling as young German Swiss and Austrian children are being drawn to their computer games and away from hobbies in general. This means there will be a vast and growing overhang of Central European stamps on the market in the coming years, and it is hard to see where there will be enough collectors to soak up the supply.
The Michel specialized catalog for the German area has specialized German philately to a level of minutia that is mind boggling, even to minds accustomed to philately. And Austria goes even further with even the paper thickness being measured on early stamps, and encyclopedias of cancellations. Austria is a small country of 8 million people. When a third or more of the adult male population collected stamps (as was the case fifty years ago) it wasn't hard to see why a Dolffus or a Wipa sold for so much money. Now that 5% collect it doesn't seem likely that these stamps can  continue to sell at the same prices that they have enjoyed until now, and the more specialized areas of German and Austrian philately should languish as well. Population growth in these countries is negative and fewer people percentage-wise collect. You do the math. Pick up any Central European auction catalog. The abundance of the material offered proves the argument. Central Europe continues to be one of the most interesting and popular areas to collect. It is just hard to see how price increases will match those that should accrue to some of the more growth oriented Asian philatelic markets.