  We studied the turbulence spectrum of the local interstellar plasma in the
direction of PSR J0437-4715, on the basis of our observations and those
reported earlier by others. We combine these data to form a structure function
for the variations of phase along the line of sight to the pulsar. For
observations that did not report them, we infer modulation indices from a
theoretical model. We find that all of the observations fit a power-law
spectrum of turbulence with index n=3.46+/-0.20. We suggest that differences
among reported values for scintillation bandwidth and timescale for this pulsar
arise from differences in observing parameters. We suggest that refractive
effects dominate for this line of sight, with refraction angle about twice the
diffraction angle at 330 MHz observing frequency. We suggest that the
scattering of this pulsar lies in a layer of enhanced turbulence, about 10 pc
from the Sun. We propose that the flux variations of the extragalactic source
PKS 0405-385 arise in the same scattering layer.
