I'm not a huge fan of the fixed subsidy, but it is deflationary long-term. Because the subsidy remains the same while the money supply grows (and may shrink due to lost coins), a graph of the inflation rate over time is steadily downward, and will eventually reach low levels. However, since their stated reason for doing this was to ensure that miners are properly incentivized, it would've made more sense to set the subsidy such that the monetary inflation rate is a constant 0.5% or something.
Sorry for the VERY late reply...
0.5% is arbitrary. We chose to make the emission non-arbitrary. We chose to make it the simplest possible, at 1 grin per second forever.
As they've designed it, the inflation rate will start out way too high,
It start out identical to Bitcoin's inflation rate, for the first 4 years. After that, it just falls much more slowly.
and then if grin survives for a very long time, it'll eventually become too low to actually meet their goal of incentivizing miners.
IMO it really doesn't matter. As you noticed above, coins inevitably get lost. At some point the yearly emission roughly balances out against yearly lost coins, defining a softcap on supply, as opposed to Bitcoin's hardcap. This guarantees that the subsidy always provides enough security for the spendable supply. Also see this Hacker News discussion
https://news.ycombinator.com/item?id=23147005Beam is too much of an obvious cheap money-grab to succeed IMO, though.
There's precious few innovative coins that rely entirely on volunteers and donations for development.
I can't think of too many besides Bitcoin, Monero, and Grin.
In addition to the money supply issue, grin is a worse store of value than Bitcoin because:
IMO the main reasons Grin is a worse store of value are 1) its perpetual emission (i.e. continued dilution), and 2) the fact that the supply is not fully (i.e. transparently) auditable.
These are also the reasons why Grin is not a direct competitor of Bitcoin.
- The dev culture is built upon a more flexible idea of system consensus. There are expected to be regular hardforks.
Only 4 hardforks were (pre)planned, at regular 6-months intervals in the first 2 years. The 3rd one is happening next month. After that, consensus model changes should be increasingly rare.
- Smart contracts are more limited, though at this time I'm not exactly sure how much more limited.
Scriptless scripts (i.e. exploiting the flexibility of Schnorr signatures) allow for multisigs, thresholds sigs, atomic swaps, discreet log contract, and payment channels.