we express total consumption Ct as the product of service consumption St and the inverse of the service consumption share Vt = St/Ct, that is, Ct = St/Vt. Thus, log total consumption growth is the difference between log service consumption growth, Δst+1, and changes in the log service consumption share,  Δvt,
                                                              Δct+1 = Δst+1 − Δvt+1.
想问的问题是，这里面的log是什么意思？
我之前的理解是log Ct=log St - log Vt，然后设小写ct=log Ct，小写st= log St 以此类推，
因此 Δct+1等于 Δlog Ct- Δlog vt？
下面是我的EXCEL数据，能否帮我看看？谢谢大家