On trickle down economics, I would say it generally refers to policies which aim to reduce the tax rates paid by the rich and this will generate wealth which will eventually trickle down to all, I haven't seen anything remotely to indicate that is the position Labour are taking.
In reality Labour is going to have to increase the tax take just to have us stand still, public finances are a mess and with demographics continuing to get more challenging, we are looking at needing to increase taxation just to maintain the current dismal level of public services.
Growth is going to be important though, we can't afford another Lost Decade and a half on that front.
So everyone keeps telling us. But can the planet actually afford more "growth", if it means increased resource consumption, increased waste, increased habitat destruction? Which it does, generally, despite visions of some clean tech-future where we all wear VR masks and work in abstract creative industries.
We're facing a future of huge population displacement due to climate change, with all the attendant wildfires, rogue storms and flooding that comes with it. That's going to cost every economy in the world untold billions of dollars.
I think it's far more likely that most nations become economically "poorer" overall as a result of this future, than somehow entering into some tech-fuelled golden-age of economic recovery. Ultimately, economic wealth is entirely underpinned by the natural wealth of the planet. That has been clear to the sane since time immemorial and is increasingly clear even to those of us in the West sold fantasy visions of endless consumption. Whilst almost every government on earth goes on about "growth", what is actually needed is fair redistribution of wealth, and the prevention of huge wealth (and therefore power) disparities within populations. Healthy societies simply do not have these vast wealth divides that have opened up in modern nations - it is hugely damaging to democracy and justice to allow them. I'd like to see a government with the courage to address these realities instead of pushing the endless dream of "growth" in a time where every single piece of feedback we are getting from the planet is asking us to stop, please, as a species.
This doesn't mean poor people getting poorer - but that is what will happen under "growth" visions. As the planet's climate becomes more and more volatile, the "size of the pie" will shrink, not grow, and the only result I can see, without radical cultural changes, will be increased hoarding of vast tranches of the remaining wealth to a few individuals and their coteries. That, essentially, is very much already underway as they and their mouthpieces continue to sell us the lie of growth, to divert from the reality: there is plenty of wealth (if we don't all remain addicted to the consumerist model), it's just incredibly unevenly distributed.