I will also point out that I am not an economist... are you a professional economist?
No, but since one can find a "professional economist" willing to back almost any fantastic assertion, I don't think this counts much against us.
In the case of SS and Medicare the money is collected and distributed (immediately). Then it is spent immediately by most of the recipients. When that money is spent, that puts the money in circulation buying goods and services which creates business opportunity.
Ahh . . . but not all expenditures produce equal "good" in the economy. When dollars are in the hands of a consumer, that individual spends them on whatever will bring him the most benefit (food, clothing, shelter, medical care, a car, a boat, etc). He will also shop around for that particular item to find the seller who gives him best value for the dollar. From these millions of possible choices, the individual will choose one, and both the seller and the buyer are winners at the end of the transaction. This competition for business consistently improves the quality of goods and services and lowers prices.
When the government takes money from the public to spend for the health care for others, there's no reason to believe that this is the best use for the money--the people who the money belonged to initially certainly didn't make the choice to spend it on health care (it got taken from them in taxes). The people who receive the health care didn't choose the sellers (in some cases) and didn't/couldn't shop for a good price (hey, it was Uncle Sam paying the bill).
But for you and I... the middle class... it is more of a pay as you go system. You paid for your parents. Your kids pay for you.... and so on.
True, except for all the "extra" money collected from me for the last 30 years--the money that went into the "trust fund". That money didn't go to any oldsters at the time, it went immediately to be spent on whatever the government bought: Tanks, welfare payments, food stamps, aid to cities, space exploration, studies on the sex life of frogs. That money is gone and the taxpayers in general don't have money to pay the "trust fund" back. Surprise! No, not really. So, lets stop the charade and make SS a true pay-as-you-go affair that balances out every year. Make the payouts match the SS taxes, or make the taxes match the payouts, but no more shifting around of money. That game is over.