it’s not just the employees, it’s the computer systems and databases
eg, let walk thru the steps of setting up an income tax:
-need a list of all taxpayers with their names, addresses and employers names and addresses: HM Revenue has that, supposed they are hard asses and won’t give it (now what, do you start going thru the phone book? voters list?)
-need a unique identifier for both taxpayers and businesses: HM Revenue has a taxpayer identifier, suppose they won’t share that database (now you need to set up a Social Security number registry)
ok so now we need a social security number registry. that number would be an identifier for payroll tax, nhs, unemployment etc. as well
creating a social security number registry would require all 5+ million scottish residents to turn up at a government office with their paper birth certificates, & have them data captured: what offices? captured by which employees? on what computer system?
and, we also need an employer registry as well...
that’s just one program...
For a programmer it looks very simple because all these steps are interlocked. For example:
A company must be registered, or else it may not buy and sell - not within the country, and certainly not across the border. To accomplish that, each company registers itself with the government via a Web form, and attaches scanned documents (incorporation papers, etc.) to the record. All done by computers. Only the cases of fraud are investigated by humans.
A company may employ only workers with Tax IDs. A Tax ID (or SSN) can be issued to a person only upon providing the name and the address. Each employee has to go to a Web site and register. A scanned birth certificate is needed only if there is no other proof of citizenship. All done by computers. Only the cases of fraud are investigated by humans.
The system works the same in the USA. There are no tax men who knock on the doors of every little business and go through the records. There are no INS (DHS) agents who routinely visit every house and ask for papers. The system is structured such that every participant in the economy is motivated to register himself, and these records are linked. A US citizen doesn't have to have an SSN; but then he will be cut off from the economy, as he cannot get a job, and cannot have a bank account, and cannot rent an apartment...
In practical terms, let's say that online papers are no good, and each citizen has to go to an office and spend 15 minutes there. How many offices one needs if the grace period is 1 year? 5 million / 260 days = 19,230 daily visits. If each office works 12 hours per day (which is easy to set up,) each employee handles 12 / 0.25 = 48 visitors per day. Let's say each office has four windows and four employees. Therefore you need 19,230 / 48 / 4 = 100 offices. This is a very small number; it's 2 offices per city, on average. Also consider that not every citizen needs the tax ID right away - children, for example.
This calculation shows that the real difficulties are not as high as one would intuitively perceive them.