Thanks for the plug, Shrub
It is an interesting and complicated question to answer. I think that every country has a lock industry. Some countries have more small companies and others only a few bigger ones. For instance Japan, to my knowledge, has only Goal, Showa, Miwa and maybe one or two others that dominate the market. The UK is dominated by lever lock entities like Chubb, Legge, Union and (someone please fill in the blanks, I can't remember!). Australia has Lockwood and Australian Lock Co (though Lockwood has been sold). Germany has quite a few (Abus, DOM, Winkhaus, Pfaffenhain, Gege, ...), Switzerland has Keso and Kaba, Austria has EVVA. France has predominantly Fichet but also a lot of smaller ones like Deny Fontaine, FTH etc. In the US Medeco, Assa Abloy, Kaba are big (who owns S&G now?). MulTLock is also quite big. But that's the catch really, there's only a few major players left in the industry globally - Assa Abloy and Kaba being the main ones. Sooner or later they are going to gobble up what's left of the decent lock making companies. Any company they don't eat will probably just fade away anyway due to the intense competition. There are also niche markets like cycle chain locks and padlocks that aren't necessarily covered by the big companies.
I think Yale is actually owned by Assa Abloy. They just kept the name.
There are some interesting sites covering eg UK lock companies in the early days. What happened on a national level in the mid to late 1900s is now happening globally.