NO.PZ2017102901000052
问题如下：
Companies X and Z have the same beginning-of-the-year book value of equity and the same tax rate. The companies have identical transactions throughout the year and report all transactions similarly except for one. Both companies acquire a £300,000 printer with a three-year useful life and a salvage value of £0 on 1 January of the new year. Company X capitalizes the printer and depreciates it on a straight-line basis, and Company Z expenses the printer. The following year-end information is gathered for Company X.
Ending shareholders’ equity: £10,000,000
Tax rate: 25%
Dividends: £0.00
Net income: £750,000
Based on the information given, Company Z’s return on equity using year-end equity will be closest to:
选项：
A. 5.4%.
B. 6.1%.
C. 7.5%.
解释：
B is correct.
Company Z’s return on equity based on year-end equity value will be 6.1%. Company Z will have an additional £200,000 of expenses compared with Company X. Company Z expensed the printer for £300,000 rather than capitalizing the printer and having a depreciation expense of £100,000 like Company X. Company Z’s net income and shareholders’ equity will be £150,000 lower (= £200,000 × 0.75) than that of Company X.
ROE=NI/equity=(750,000-150,000)/(10,000,000-150,000)=600,000/9,850,000=0.
题目假设X公司和Z公司财务数据都是一样的，除了对一笔printer采购支出的处理之外。X公司是资本化，而Z公司是费用化，题目给了X公司的财务数据，让计算Z公司的ROE。我们根据题目给的数据可以计算出来X公司的ROE，在此基础上进行调整就可以得到Z公司的ROE。调整的时候就要考虑资本化和费用化导致的两个公司NI和Equity的不同。
看NI的不同，我们就要看损益表：X公司资本化，printer被当做资产处理，损益表中会有一笔100,000的折旧费用。Z公司费用化，printer的全部成本都算作expense，因此Z公司损益表中会有一笔300,000的expense。两个公司损益表中费用的差额为200,000，由于有税收的影响，最终NI的差异是200,000*（1-25%）=150,000，也就是Z公司的NI比X公司的NI少150,000。
再比较equity的不同，因为其他条件都相同，两个公司equity受到的影响就只有retained earning的影响，这个也是跟NI相关联，Z公司NI比X公司少150,000，那么Z公司的equity也会比X公司的equity少150,000。
最后再调整X公司的ROE以得到Z公司的ROE：
（750,000-150,000）/（10,000,000-150,000）=600,000/9,850,000=0.61
如标题所示，其他的回答太正式了，没太理解哈
