# Arranging carboxylic acids by increasing acidity

Why is $\ce{Ph-CH2-COOH}$ more acidic than $\ce{CH3COOH}$ although the equilibrium of ionization lies mainly backward for both of them?

Attempt:

In the ionized form of $\ce{Ph-CH2-COOH}$ we have a $\ce{Ph-CH2}$-group donating its electron to carbonyl carbon while in case of acetic acid we have a methyl group donating its electron to the carbonyl carbon.

But which one of them is stabilized more?

The $\mathrm pK_\mathrm a$ difference between phenylacetic acid and acetic acid is around 0.5 and the trends become more obvious when other arylalkanoic acids are included in the comparison. Numbers in red are the $\mathrm pK_\mathrm a$ values.
Would you think that there is a $-I$ effect of the phenyl substituent on the $\ce{-COOH}$ group?