When is subsidy necessary in comodity supply

Amachine purchased three years ago for $720,000 has a current book value using straight-line depreciation of $400,000: its operating expenses are $60,000 per year. a replacement machine would cost $480,000, have a useful life of nine years, and would require $26,000 per year in operating expenses. it has an expected salvage value of $130,000 after nine years. the current disposal value of the old machine is $170,000: if it is kept 9 more years, its residual value would be $20,000. calculate the total costs in keeping the old machine and purchase a new machine. should the old machine be replaced?

Afreelance​ singer-songwriter is planning the restoration of a recently purchased civil​ war-era farmhouse. while he professes an enjoyment​ of, and talent in the construction​ trades, the theory of comparative advantage implies that a. the value of what he imports​ (in this​ case, professional contractor​ services) must equal the value of what he exports​ (songs). b. he should concentrate on the restoration work since his​ out-of-pocket costs will be much lower than if he hires professionals. c. ​self-sufficiency is​ advantageous, hence he should split his time between music and construction. d. the income lost while away from music will likely exceed the savings realized by doing the work​ himself, thus, he should hire professionals to do the restoration work. e. he ought to do as much of the work himself as possible since imports​ (in this​ case, professional contractor​ services) should always be restricted to those things that cannot be done internall

After the 2008 recession, the amount of reserves in the us banking system increased. because of federal reserve actions, required reserves increased from $44 billion to $60 billion. however, banks started holding more reserves than required. by january 2009, banks were holding $900 billion in excess reserves. the federal reserve started paying interest on the excess reserves that the banks held. what possible impact will these unused reserves have on the economy?