Why does a doppler red shift prove expansion?

My question boils down to this. If the Universe was contracting the stars closer to the center would move faster to the middle than stars that were further away from the center.

That would also produce a red doppler shift. So why is it that the red shift is always linked to expansion? Human optimism?

Thanks,

Andrew

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Also, faraway galaxies would be moving more rapidly towards us than more nearby galaxies, so faraway galaxies would be more blueshifted: Hubble's Law $$v = HD$$ would still hold, but $H$ would be negative. The larger the distance $D$, the more negative $v$ would be.