Dear STANers,

I was fitting a simple example with the model below and I am wondering what is the “default prior” which is used in this case.

I would think that it is a completely uniform/flat prior. Is that the case ?

```
data {
int<lower=0> N;
vector[N] x;
vector[N] y;
}
parameters {
real alpha;
real beta;
real<lower=0> sigma;
}
model {
for (n in 1:N) {
y[n] ~ normal(alpha + beta * x[n], sigma);
}
}
```

Cheers,

Jozsef