Changes in version 0.1.0                        

  - Added a NEWS.md file to track changes to the package.
  - io_check_axes() is now called by io_leontief_inverse() and
    io_ghosh_inverse() to validate that input and output industry axes
    match before matrix inversion, preventing errors from mismatched
    tables.
  - io_check_totals() now validates total_tolerance with a clearer error
    message.
  - io_downstreamness() returns the column sums of the Leontief inverse,
    i.e. the output multiplier (backward linkage), with a normalize
    option to obtain the power of dispersion.
  - io_input_coef(), io_output_coef(), io_leontief_inverse(), and
    io_ghosh_inverse() now report invalid open_economy values against
    the calling function with a clearer error message.
  - io_reclass() now validates from_col, to_col, weight_col,
    weight_tolerance, and check_axes.
  - io_spectral_embedding() is now marked as experimental.
  - io_spectral_embedding() returns the Laplacian spectral embedding
    (Fiedler vector) of the domestic production network, minimizing the
    graph Dirichlet energy; pair it with io_trophic_level() for a
    directed supply-chain map.
  - io_spectral_embedding(), io_trophic_incoherence() and
    io_trophic_level() now inform when they implicitly convert a
    competitive import type table to noncompetitive import type before
    building the industry network.
  - io_spectral_embedding(), io_trophic_incoherence() and
    io_trophic_level() now inform and zero out negative domestic
    intermediate transactions (e.g. from byproduct treatment such as the
    Stone method) before building the industry network, instead of
    producing an ill-defined result.
  - io_spectral_embedding() now reports an invalid dims argument with a
    clearer error message.
  - io_streamness_length() is a new function that returns the total
    length of the supply chain passing through each industry, computed
    as the sum of io_upstreamness() and io_downstreamness(), following
    Antràs and Chor (2018).
  - io_streamness_position() is a new experimental function that returns
    the net position of each industry within the supply chain, derived
    from io_upstreamness() and io_downstreamness(), with a type argument
    to choose between their difference, a [-1, 1]-bounded relative
    difference, or a log ratio.
  - io_table_regional() and io_table_multiregional() now validate
    check_axes, competitive_import, and total_tolerance.
  - io_table_to_competitive_import(),
    io_table_to_noncompetitive_import(), and io_table_to_regional() now
    validate their sector-name and tolerance arguments.
  - io_table_to_noncompetitive_import() no longer leaves a leftover
    zero-valued import sector on the output axis when converting from a
    competitive import type table.
  - io_total_input() and io_total_output() now validate same_region.
  - io_trophic_incoherence() returns the trophic incoherence of the
    domestic production network.
  - io_trophic_level() returns the directed-network trophic level of
    each industry, following MacKay, Johnson and Sansom (2020).
  - io_upstreamness() returns the row sums of the Ghosh inverse, i.e.
    the forward linkage.