經濟成長 - 經濟

※ 引述《betray911015 (回頭太難)》之銘言：
: １假設每一工人小時的資本每年成長百分之三，而技術變動則每年成長
: 　百分之二。若使用三分之一原則，我們可以推論每一工人小時的實質
: 　國內生產毛額會每年成長百分之？
: 我的算法：　△Y △A △K
: ------ = ----- + -------
: Y A K
: = 2% +3%*(1/3)
: = 3%
: 我這樣算對嗎？？
: 2.If the U.S. production funciton is Cobb-Douglas with capital share
: 0.3, output growth is 3 percent per year, depreciation is 4 percent
: per year, and the Golden Rule steady-state capital-output raio
: is 4.29, to reach the Golden Rule steady state, the saving rate must
: be:
: a.less than 18 percent
: b.more than 18 percent and less than 23 percent
: c.more than 23 percent and less than 28 percent
: d.more than 28 percent and less than 33 percent
: e.more than 33 percent
: 這題答案為 d，要怎麼算??

Y = N^0.7 * K^0.3 y = k^0.3 = f(k)

golden rule的k*由f'(k) = n + d

0.3 * 4.29^-(0.7) = n + d 可算出n + d

steady-state = sy = ( n + d ) k

可得s = 0.3

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