Good questiopn Blown! Yes the size of the population has alot to do with it but there are other very sinificant factors unique to california that makes it such an economic powerhouse.
Ffirst of all this state has an enormous agricultural business that has been virtualy recession proof over the last 50 years. californis farmers ship more produce per year through ou the country and for tht matter the world...than any other region on the planet! Thats right the california farmer lands of the Central Valley and the Imperial Valley grow more crops than any othe region in the world!!!
Why? Primarily because we can grow more crops per year than most regions because we water is plenty full. wev artificially irragate with water from the colorado river through out the eastern areas of riverside and imperialm valley areas. and from the irragation net work in norcal and the water availabilty to the central valley areas. Even LA, Orange and ventura counties have a huge agrow business infrastructure. And because of willingness to employ science and chemical assistance California just grows more food than any body. Including all types and it is in demand all over the world.
An other reason is that the west has had an emormous steady population migration for fifty years. that along with other factors has created a real estate industry that has had for the most part the longest steadiest growth period than anyother region in the country. people have enjoyed greater inflation of their equity in ca real estae than any whwere else in the world over a longer period than any other area.
Whether your a commercial investor or a residential home owner...your property has grown more valuable in California than any where in the country. what has that ment well..although californians dn't save as much of their income as other people have in other parts of the country..it hasn't mattered cuz in CA we dont save money we just buy the biggest home we can afford monthly and then we just hang on to it and watch it go up in value and make us 100,000's of dollars in just several years.
you cant do that in Fargo ND. So then people either trade up or borrow the equity out of their houses for cars, furniture, tv's, xmas presents and EVEN BOATS AND RV'S! all of this activity fuels the California economy.
Also we have more international ports of entry than any other state. That includes San Francisco, Oakland, Long Beach, San Pedro, and L.A. Harbors. Moving more tonnage combined than any other state in the union. Not including that ca has more international airports than any other state in the union. i cant even name them al!
All this means jobs which means higher wages. Yes the shear size of the state is overwhelming. Now figure in some nitch markets like silicaon valley, hollywood ect and the state has real economic power. also it doesn't hurt having the most moderate weather in the country. Also our Pacific coast line has created an enormous tourist industry! well those are just a few of the reasons not including the oil busivess as well as the military bases..ad it all up and California really is the 7th or 8th largest economy in the world!!!!